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d2febafdcd
Add missing include statements, add missing "static" qualifiers or remove functions which are not used at all. Signed-off-by: Stefan Weil <sw@weilnetz.de>
2678 lines
98 KiB
C++
2678 lines
98 KiB
C++
/**********************************************************************
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* File: makerow.cpp (Formerly makerows.c)
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* Description: Code to arrange blobs into rows of text.
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* Author: Ray Smith
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* Created: Mon Sep 21 14:34:48 BST 1992
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*
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* (C) Copyright 1992, Hewlett-Packard Ltd.
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** Licensed under the Apache License, Version 2.0 (the "License");
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** you may not use this file except in compliance with the License.
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** You may obtain a copy of the License at
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** http://www.apache.org/licenses/LICENSE-2.0
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** Unless required by applicable law or agreed to in writing, software
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** distributed under the License is distributed on an "AS IS" BASIS,
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** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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** See the License for the specific language governing permissions and
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** limitations under the License.
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*
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**********************************************************************/
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#include <vector> // for std::vector
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#include "blobbox.h"
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#include "ccstruct.h"
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#include "detlinefit.h"
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#include "statistc.h"
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#include "drawtord.h"
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#include "blkocc.h"
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#include "sortflts.h"
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#include "oldbasel.h"
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#include "textord.h"
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#include "tordmain.h"
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#include "underlin.h"
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#include "makerow.h"
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#include "tprintf.h"
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#include "tovars.h"
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// Include automatically generated configuration file if running autoconf.
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#ifdef HAVE_CONFIG_H
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#include "config_auto.h"
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#endif
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#include <algorithm>
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BOOL_VAR(textord_heavy_nr, FALSE, "Vigorously remove noise");
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BOOL_VAR(textord_show_initial_rows, FALSE, "Display row accumulation");
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BOOL_VAR(textord_show_parallel_rows, FALSE, "Display page correlated rows");
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BOOL_VAR(textord_show_expanded_rows, FALSE, "Display rows after expanding");
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BOOL_VAR(textord_show_final_rows, FALSE, "Display rows after final fitting");
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BOOL_VAR(textord_show_final_blobs, FALSE, "Display blob bounds after pre-ass");
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BOOL_VAR(textord_test_landscape, FALSE, "Tests refer to land/port");
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BOOL_VAR(textord_parallel_baselines, TRUE, "Force parallel baselines");
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BOOL_VAR(textord_straight_baselines, FALSE, "Force straight baselines");
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BOOL_VAR(textord_old_baselines, TRUE, "Use old baseline algorithm");
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BOOL_VAR(textord_old_xheight, FALSE, "Use old xheight algorithm");
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BOOL_VAR(textord_fix_xheight_bug, TRUE, "Use spline baseline");
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BOOL_VAR(textord_fix_makerow_bug, TRUE, "Prevent multiple baselines");
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BOOL_VAR(textord_debug_xheights, FALSE, "Test xheight algorithms");
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BOOL_VAR(textord_biased_skewcalc, TRUE, "Bias skew estimates with line length");
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BOOL_VAR(textord_interpolating_skew, TRUE, "Interpolate across gaps");
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INT_VAR(textord_skewsmooth_offset, 4, "For smooth factor");
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INT_VAR(textord_skewsmooth_offset2, 1, "For smooth factor");
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INT_VAR(textord_test_x, -INT32_MAX, "coord of test pt");
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INT_VAR(textord_test_y, -INT32_MAX, "coord of test pt");
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INT_VAR(textord_min_blobs_in_row, 4, "Min blobs before gradient counted");
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INT_VAR(textord_spline_minblobs, 8, "Min blobs in each spline segment");
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INT_VAR(textord_spline_medianwin, 6, "Size of window for spline segmentation");
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INT_VAR(textord_max_blob_overlaps, 4,
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"Max number of blobs a big blob can overlap");
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INT_VAR(textord_min_xheight, 10, "Min credible pixel xheight");
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double_VAR(textord_spline_shift_fraction, 0.02,
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"Fraction of line spacing for quad");
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double_VAR(textord_spline_outlier_fraction, 0.1,
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"Fraction of line spacing for outlier");
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double_VAR(textord_skew_ile, 0.5, "Ile of gradients for page skew");
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double_VAR(textord_skew_lag, 0.02, "Lag for skew on row accumulation");
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double_VAR(textord_linespace_iqrlimit, 0.2, "Max iqr/median for linespace");
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double_VAR(textord_width_limit, 8, "Max width of blobs to make rows");
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double_VAR(textord_chop_width, 1.5, "Max width before chopping");
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double_VAR(textord_expansion_factor, 1.0,
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"Factor to expand rows by in expand_rows");
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double_VAR(textord_overlap_x, 0.375, "Fraction of linespace for good overlap");
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double_VAR(textord_minxh, 0.25, "fraction of linesize for min xheight");
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double_VAR(textord_min_linesize, 1.25, "* blob height for initial linesize");
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double_VAR(textord_excess_blobsize, 1.3,
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"New row made if blob makes row this big");
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double_VAR(textord_occupancy_threshold, 0.4, "Fraction of neighbourhood");
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double_VAR(textord_underline_width, 2.0, "Multiple of line_size for underline");
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double_VAR(textord_min_blob_height_fraction, 0.75,
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"Min blob height/top to include blob top into xheight stats");
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double_VAR(textord_xheight_mode_fraction, 0.4,
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"Min pile height to make xheight");
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double_VAR(textord_ascheight_mode_fraction, 0.08,
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"Min pile height to make ascheight");
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double_VAR(textord_descheight_mode_fraction, 0.08,
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"Min pile height to make descheight");
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double_VAR(textord_ascx_ratio_min, 1.25, "Min cap/xheight");
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double_VAR(textord_ascx_ratio_max, 1.8, "Max cap/xheight");
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double_VAR(textord_descx_ratio_min, 0.25, "Min desc/xheight");
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double_VAR(textord_descx_ratio_max, 0.6, "Max desc/xheight");
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double_VAR(textord_xheight_error_margin, 0.1, "Accepted variation");
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INT_VAR(textord_lms_line_trials, 12, "Number of linew fits to do");
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BOOL_VAR(textord_new_initial_xheight, TRUE, "Use test xheight mechanism");
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BOOL_VAR(textord_debug_blob, FALSE, "Print test blob information");
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#define MAX_HEIGHT_MODES 12
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const int kMinLeaderCount = 5;
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// Factored-out helper to build a single row from a list of blobs.
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// Returns the mean blob size.
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static float MakeRowFromBlobs(float line_size,
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BLOBNBOX_IT* blob_it, TO_ROW_IT* row_it) {
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blob_it->sort(blob_x_order);
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blob_it->move_to_first();
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TO_ROW* row = nullptr;
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float total_size = 0.0f;
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int blob_count = 0;
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// Add all the blobs to a single TO_ROW.
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for (; !blob_it->empty(); blob_it->forward()) {
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BLOBNBOX* blob = blob_it->extract();
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int top = blob->bounding_box().top();
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int bottom = blob->bounding_box().bottom();
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if (row == nullptr) {
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row = new TO_ROW(blob, top, bottom, line_size);
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row_it->add_before_then_move(row);
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} else {
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row->add_blob(blob, top, bottom, line_size);
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}
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total_size += top - bottom;
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++blob_count;
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}
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return blob_count > 0 ? total_size / blob_count : total_size;
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}
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// Helper to make a row using the children of a single blob.
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// Returns the mean size of the blobs created.
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static float MakeRowFromSubBlobs(TO_BLOCK* block, C_BLOB* blob,
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TO_ROW_IT* row_it) {
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// The blobs made from the children will go in the small_blobs list.
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BLOBNBOX_IT bb_it(&block->small_blobs);
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C_OUTLINE_IT ol_it(blob->out_list());
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// Get the children.
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ol_it.set_to_list(ol_it.data()->child());
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if (ol_it.empty())
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return 0.0f;
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for (ol_it.mark_cycle_pt(); !ol_it.cycled_list(); ol_it.forward()) {
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// Deep copy the child outline and use that to make a blob.
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C_BLOB* blob = new C_BLOB(C_OUTLINE::deep_copy(ol_it.data()));
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// Correct direction as needed.
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blob->CheckInverseFlagAndDirection();
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BLOBNBOX* bbox = new BLOBNBOX(blob);
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bb_it.add_after_then_move(bbox);
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}
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// Now we can make a row from the blobs.
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return MakeRowFromBlobs(block->line_size, &bb_it, row_it);
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}
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/**
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* @name make_single_row
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*
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* Arrange the blobs into a single row... well actually, if there is
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* only a single blob, it makes 2 rows, in case the top-level blob
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* is a container of the real blobs to recognize.
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*/
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float make_single_row(ICOORD page_tr, bool allow_sub_blobs,
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TO_BLOCK* block, TO_BLOCK_LIST* blocks) {
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BLOBNBOX_IT blob_it = &block->blobs;
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TO_ROW_IT row_it = block->get_rows();
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// Include all the small blobs and large blobs.
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blob_it.add_list_after(&block->small_blobs);
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blob_it.add_list_after(&block->noise_blobs);
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blob_it.add_list_after(&block->large_blobs);
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if (block->blobs.singleton() && allow_sub_blobs) {
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blob_it.move_to_first();
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float size = MakeRowFromSubBlobs(block, blob_it.data()->cblob(), &row_it);
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if (size > block->line_size)
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block->line_size = size;
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} else if (block->blobs.empty()) {
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// Make a fake blob.
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C_BLOB* blob = C_BLOB::FakeBlob(block->block->pdblk.bounding_box());
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// The blobnbox owns the blob.
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BLOBNBOX* bblob = new BLOBNBOX(blob);
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blob_it.add_after_then_move(bblob);
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}
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MakeRowFromBlobs(block->line_size, &blob_it, &row_it);
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// Fit an LMS line to the rows.
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for (row_it.mark_cycle_pt(); !row_it.cycled_list(); row_it.forward())
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fit_lms_line(row_it.data());
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float gradient;
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float fit_error;
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// Compute the skew based on the fitted line.
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compute_page_skew(blocks, gradient, fit_error);
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return gradient;
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}
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/**
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* @name make_rows
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*
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* Arrange the blobs into rows.
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*/
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float make_rows(ICOORD page_tr, TO_BLOCK_LIST *port_blocks) {
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float port_m; // global skew
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float port_err; // global noise
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TO_BLOCK_IT block_it; // iterator
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block_it.set_to_list(port_blocks);
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for (block_it.mark_cycle_pt(); !block_it.cycled_list();
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block_it.forward())
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make_initial_textrows(page_tr, block_it.data(), FCOORD(1.0f, 0.0f),
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!textord_test_landscape);
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// compute globally
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compute_page_skew(port_blocks, port_m, port_err);
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block_it.set_to_list(port_blocks);
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for (block_it.mark_cycle_pt(); !block_it.cycled_list(); block_it.forward()) {
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cleanup_rows_making(page_tr, block_it.data(), port_m, FCOORD(1.0f, 0.0f),
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block_it.data()->block->pdblk.bounding_box().left(),
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!textord_test_landscape);
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}
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return port_m; // global skew
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}
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/**
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* @name make_initial_textrows
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*
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* Arrange the good blobs into rows of text.
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*/
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void make_initial_textrows( //find lines
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ICOORD page_tr,
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TO_BLOCK* block, //block to do
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FCOORD rotation, //for drawing
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bool testing_on //correct orientation
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) {
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TO_ROW_IT row_it = block->get_rows ();
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#ifndef GRAPHICS_DISABLED
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ScrollView::Color colour; //of row
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if (textord_show_initial_rows && testing_on) {
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if (to_win == nullptr)
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create_to_win(page_tr);
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}
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#endif
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//guess skew
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assign_blobs_to_rows (block, nullptr, 0, TRUE, TRUE, textord_show_initial_rows && testing_on);
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row_it.move_to_first ();
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for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ())
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fit_lms_line (row_it.data ());
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#ifndef GRAPHICS_DISABLED
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if (textord_show_initial_rows && testing_on) {
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colour = ScrollView::RED;
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for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
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plot_to_row (row_it.data (), colour, rotation);
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colour = (ScrollView::Color) (colour + 1);
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if (colour > ScrollView::MAGENTA)
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colour = ScrollView::RED;
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}
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}
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#endif
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}
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/**
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* @name fit_lms_line
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*
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* Fit an LMS line to a row.
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*/
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void fit_lms_line(TO_ROW *row) {
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float m, c; // fitted line
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tesseract::DetLineFit lms;
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BLOBNBOX_IT blob_it = row->blob_list();
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for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
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const TBOX& box = blob_it.data()->bounding_box();
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lms.Add(ICOORD((box.left() + box.right()) / 2, box.bottom()));
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}
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double error = lms.Fit(&m, &c);
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row->set_line(m, c, error);
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}
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/**
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* @name compute_page_skew
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*
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* Compute the skew over a full page by averaging the gradients over
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* all the lines. Get the error of the same row.
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*/
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void compute_page_skew( //get average gradient
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TO_BLOCK_LIST *blocks, //list of blocks
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float &page_m, //average gradient
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float &page_err //average error
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) {
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int32_t row_count; //total rows
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int32_t blob_count; //total_blobs
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int32_t row_err; //integer error
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int32_t row_index; //of total
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TO_ROW *row; //current row
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TO_BLOCK_IT block_it = blocks; //iterator
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row_count = 0;
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blob_count = 0;
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for (block_it.mark_cycle_pt (); !block_it.cycled_list ();
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block_it.forward ()) {
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POLY_BLOCK* pb = block_it.data()->block->pdblk.poly_block();
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if (pb != nullptr && !pb->IsText())
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continue; // Pretend non-text blocks don't exist.
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row_count += block_it.data ()->get_rows ()->length ();
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//count up rows
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TO_ROW_IT row_it(block_it.data()->get_rows());
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for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ())
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blob_count += row_it.data ()->blob_list ()->length ();
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}
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if (row_count == 0) {
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page_m = 0.0f;
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page_err = 0.0f;
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return;
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}
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// of rows
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std::vector<float> gradients(blob_count);
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// of rows
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std::vector<float> errors(blob_count);
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row_index = 0;
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for (block_it.mark_cycle_pt (); !block_it.cycled_list ();
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block_it.forward ()) {
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POLY_BLOCK* pb = block_it.data()->block->pdblk.poly_block();
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if (pb != nullptr && !pb->IsText())
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continue; // Pretend non-text blocks don't exist.
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TO_ROW_IT row_it(block_it.data ()->get_rows());
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for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
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row = row_it.data ();
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blob_count = row->blob_list ()->length ();
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row_err = (int32_t) ceil (row->line_error ());
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if (row_err <= 0)
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row_err = 1;
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if (textord_biased_skewcalc) {
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blob_count /= row_err;
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for (blob_count /= row_err; blob_count > 0; blob_count--) {
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gradients[row_index] = row->line_m ();
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errors[row_index] = row->line_error ();
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row_index++;
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}
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}
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else if (blob_count >= textord_min_blobs_in_row) {
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//get gradient
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gradients[row_index] = row->line_m ();
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errors[row_index] = row->line_error ();
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row_index++;
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}
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}
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}
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if (row_index == 0) {
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//desperate
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for (block_it.mark_cycle_pt (); !block_it.cycled_list ();
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block_it.forward ()) {
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POLY_BLOCK* pb = block_it.data()->block->pdblk.poly_block();
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if (pb != nullptr && !pb->IsText())
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continue; // Pretend non-text blocks don't exist.
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TO_ROW_IT row_it(block_it.data()->get_rows());
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for (row_it.mark_cycle_pt (); !row_it.cycled_list ();
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row_it.forward ()) {
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row = row_it.data ();
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gradients[row_index] = row->line_m ();
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errors[row_index] = row->line_error ();
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row_index++;
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}
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}
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}
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row_count = row_index;
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row_index = choose_nth_item ((int32_t) (row_count * textord_skew_ile),
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&gradients[0], row_count);
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page_m = gradients[row_index];
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row_index = choose_nth_item ((int32_t) (row_count * textord_skew_ile),
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&errors[0], row_count);
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page_err = errors[row_index];
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}
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const double kNoiseSize = 0.5; // Fraction of xheight.
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const int kMinSize = 8; // Min pixels to be xheight.
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/**
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* Return true if the dot looks like it is part of the i.
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* Doesn't work for any other diacritical.
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*/
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static bool dot_of_i(BLOBNBOX* dot, BLOBNBOX* i, TO_ROW* row) {
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const TBOX& ibox = i->bounding_box();
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const TBOX& dotbox = dot->bounding_box();
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// Must overlap horizontally by enough and be high enough.
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int overlap = std::min(dotbox.right(), ibox.right()) -
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std::max(dotbox.left(), ibox.left());
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if (ibox.height() <= 2 * dotbox.height() ||
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(overlap * 2 < ibox.width() && overlap < dotbox.width()))
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return false;
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// If the i is tall and thin then it is good.
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if (ibox.height() > ibox.width() * 2)
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return true; // The i or ! must be tall and thin.
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// It might still be tall and thin, but it might be joined to something.
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// So search the outline for a piece of large height close to the edges
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// of the dot.
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const double kHeightFraction = 0.6;
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double target_height = std::min(dotbox.bottom(), ibox.top());
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target_height -= row->line_m()*dotbox.left() + row->line_c();
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target_height *= kHeightFraction;
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int left_min = dotbox.left() - dotbox.width();
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int middle = (dotbox.left() + dotbox.right())/2;
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int right_max = dotbox.right() + dotbox.width();
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int left_miny = 0;
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int left_maxy = 0;
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int right_miny = 0;
|
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int right_maxy = 0;
|
|
bool found_left = false;
|
|
bool found_right = false;
|
|
bool in_left = false;
|
|
bool in_right = false;
|
|
C_BLOB* blob = i->cblob();
|
|
C_OUTLINE_IT o_it = blob->out_list();
|
|
for (o_it.mark_cycle_pt(); !o_it.cycled_list(); o_it.forward()) {
|
|
C_OUTLINE* outline = o_it.data();
|
|
int length = outline->pathlength();
|
|
ICOORD pos = outline->start_pos();
|
|
for (int step = 0; step < length; pos += outline->step(step++)) {
|
|
int x = pos.x();
|
|
int y = pos.y();
|
|
if (x >= left_min && x < middle && !found_left) {
|
|
// We are in the left part so find min and max y.
|
|
if (in_left) {
|
|
if (y > left_maxy) left_maxy = y;
|
|
if (y < left_miny) left_miny = y;
|
|
} else {
|
|
left_maxy = left_miny = y;
|
|
in_left = true;
|
|
}
|
|
} else if (in_left) {
|
|
// We just left the left so look for size.
|
|
if (left_maxy - left_miny > target_height) {
|
|
if (found_right)
|
|
return true;
|
|
found_left = true;
|
|
}
|
|
in_left = false;
|
|
}
|
|
if (x <= right_max && x > middle && !found_right) {
|
|
// We are in the right part so find min and max y.
|
|
if (in_right) {
|
|
if (y > right_maxy) right_maxy = y;
|
|
if (y < right_miny) right_miny = y;
|
|
} else {
|
|
right_maxy = right_miny = y;
|
|
in_right = true;
|
|
}
|
|
} else if (in_right) {
|
|
// We just left the right so look for size.
|
|
if (right_maxy - right_miny > target_height) {
|
|
if (found_left)
|
|
return true;
|
|
found_right = true;
|
|
}
|
|
in_right = false;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void vigorous_noise_removal(TO_BLOCK* block) {
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
TO_ROW* row = row_it.data();
|
|
BLOBNBOX_IT b_it = row->blob_list();
|
|
// Estimate the xheight on the row.
|
|
int max_height = 0;
|
|
for (b_it.mark_cycle_pt(); !b_it.cycled_list(); b_it.forward()) {
|
|
BLOBNBOX* blob = b_it.data();
|
|
if (blob->bounding_box().height() > max_height)
|
|
max_height = blob->bounding_box().height();
|
|
}
|
|
STATS hstats(0, max_height + 1);
|
|
for (b_it.mark_cycle_pt(); !b_it.cycled_list(); b_it.forward()) {
|
|
BLOBNBOX* blob = b_it.data();
|
|
int height = blob->bounding_box().height();
|
|
if (height >= kMinSize)
|
|
hstats.add(blob->bounding_box().height(), 1);
|
|
}
|
|
float xheight = hstats.median();
|
|
// Delete small objects.
|
|
BLOBNBOX* prev = nullptr;
|
|
for (b_it.mark_cycle_pt(); !b_it.cycled_list(); b_it.forward()) {
|
|
BLOBNBOX* blob = b_it.data();
|
|
const TBOX& box = blob->bounding_box();
|
|
if (box.height() < kNoiseSize * xheight) {
|
|
// Small so delete unless it looks like an i dot.
|
|
if (prev != nullptr) {
|
|
if (dot_of_i(blob, prev, row))
|
|
continue; // Looks OK.
|
|
}
|
|
if (!b_it.at_last()) {
|
|
BLOBNBOX* next = b_it.data_relative(1);
|
|
if (dot_of_i(blob, next, row))
|
|
continue; // Looks OK.
|
|
}
|
|
// It might be noise so get rid of it.
|
|
delete blob->cblob();
|
|
delete b_it.extract();
|
|
} else {
|
|
prev = blob;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* cleanup_rows_making
|
|
*
|
|
* Remove overlapping rows and fit all the blobs to what's left.
|
|
*/
|
|
void cleanup_rows_making( //find lines
|
|
ICOORD page_tr, //top right
|
|
TO_BLOCK* block, //block to do
|
|
float gradient, //gradient to fit
|
|
FCOORD rotation, //for drawing
|
|
int32_t block_edge, //edge of block
|
|
bool testing_on //correct orientation
|
|
) {
|
|
//iterators
|
|
BLOBNBOX_IT blob_it = &block->blobs;
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (textord_show_parallel_rows && testing_on) {
|
|
if (to_win == nullptr)
|
|
create_to_win(page_tr);
|
|
}
|
|
#endif
|
|
//get row coords
|
|
fit_parallel_rows(block,
|
|
gradient,
|
|
rotation,
|
|
block_edge,
|
|
textord_show_parallel_rows && testing_on);
|
|
delete_non_dropout_rows(block,
|
|
gradient,
|
|
rotation,
|
|
block_edge,
|
|
textord_show_parallel_rows && testing_on);
|
|
expand_rows(page_tr, block, gradient, rotation, block_edge, testing_on);
|
|
blob_it.set_to_list (&block->blobs);
|
|
row_it.set_to_list (block->get_rows ());
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ())
|
|
blob_it.add_list_after (row_it.data ()->blob_list ());
|
|
//give blobs back
|
|
assign_blobs_to_rows (block, &gradient, 1, FALSE, FALSE, FALSE);
|
|
//now new rows must be genuine
|
|
blob_it.set_to_list (&block->blobs);
|
|
blob_it.add_list_after (&block->large_blobs);
|
|
assign_blobs_to_rows (block, &gradient, 2, TRUE, TRUE, FALSE);
|
|
//safe to use big ones now
|
|
blob_it.set_to_list (&block->blobs);
|
|
//throw all blobs in
|
|
blob_it.add_list_after (&block->noise_blobs);
|
|
blob_it.add_list_after (&block->small_blobs);
|
|
assign_blobs_to_rows (block, &gradient, 3, FALSE, FALSE, FALSE);
|
|
}
|
|
|
|
/**
|
|
* delete_non_dropout_rows
|
|
*
|
|
* Compute the linespacing and offset.
|
|
*/
|
|
void delete_non_dropout_rows( //find lines
|
|
TO_BLOCK* block, //block to do
|
|
float gradient, //global skew
|
|
FCOORD rotation, //deskew vector
|
|
int32_t block_edge, //left edge
|
|
bool testing_on //correct orientation
|
|
) {
|
|
TBOX block_box; //deskewed block
|
|
int32_t max_y; //in block
|
|
int32_t min_y;
|
|
int32_t line_index; //of scan line
|
|
int32_t line_count; //no of scan lines
|
|
int32_t distance; //to drop-out
|
|
int32_t xleft; //of block
|
|
int32_t ybottom; //of block
|
|
TO_ROW *row; //current row
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
BLOBNBOX_IT blob_it = &block->blobs;
|
|
|
|
if (row_it.length () == 0)
|
|
return; //empty block
|
|
block_box = deskew_block_coords (block, gradient);
|
|
xleft = block->block->pdblk.bounding_box ().left ();
|
|
ybottom = block->block->pdblk.bounding_box ().bottom ();
|
|
min_y = block_box.bottom () - 1;
|
|
max_y = block_box.top () + 1;
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
line_index = (int32_t) floor (row_it.data ()->intercept ());
|
|
if (line_index <= min_y)
|
|
min_y = line_index - 1;
|
|
if (line_index >= max_y)
|
|
max_y = line_index + 1;
|
|
}
|
|
line_count = max_y - min_y + 1;
|
|
if (line_count <= 0)
|
|
return; //empty block
|
|
// change in occupation
|
|
std::vector<int32_t> deltas(line_count);
|
|
// of pixel coords
|
|
std::vector<int32_t> occupation(line_count);
|
|
|
|
compute_line_occupation(block, gradient, min_y, max_y, &occupation[0], &deltas[0]);
|
|
compute_occupation_threshold ((int32_t)
|
|
ceil (block->line_spacing *
|
|
(tesseract::CCStruct::kDescenderFraction +
|
|
tesseract::CCStruct::kAscenderFraction)),
|
|
(int32_t) ceil (block->line_spacing *
|
|
(tesseract::CCStruct::kXHeightFraction +
|
|
tesseract::CCStruct::kAscenderFraction)),
|
|
max_y - min_y + 1, &occupation[0], &deltas[0]);
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (testing_on) {
|
|
draw_occupation(xleft, ybottom, min_y, max_y, &occupation[0], &deltas[0]);
|
|
}
|
|
#endif
|
|
compute_dropout_distances(&occupation[0], &deltas[0], line_count);
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
row = row_it.data ();
|
|
line_index = (int32_t) floor (row->intercept ());
|
|
distance = deltas[line_index - min_y];
|
|
if (find_best_dropout_row (row, distance, block->line_spacing / 2,
|
|
line_index, &row_it, testing_on)) {
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (testing_on)
|
|
plot_parallel_row(row, gradient, block_edge,
|
|
ScrollView::WHITE, rotation);
|
|
#endif
|
|
blob_it.add_list_after (row_it.data ()->blob_list ());
|
|
delete row_it.extract (); //too far away
|
|
}
|
|
}
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
blob_it.add_list_after (row_it.data ()->blob_list ());
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* @name find_best_dropout_row
|
|
*
|
|
* Delete this row if it has a neighbour with better dropout characteristics.
|
|
* TRUE is returned if the row should be deleted.
|
|
*/
|
|
bool find_best_dropout_row( //find neighbours
|
|
TO_ROW* row, //row to test
|
|
int32_t distance, //dropout dist
|
|
float dist_limit, //threshold distance
|
|
int32_t line_index, //index of row
|
|
TO_ROW_IT* row_it, //current position
|
|
bool testing_on //correct orientation
|
|
) {
|
|
int32_t next_index; // of neighbouring row
|
|
int32_t row_offset; //from current row
|
|
int32_t abs_dist; //absolute distance
|
|
int8_t row_inc; //increment to row_index
|
|
TO_ROW *next_row; //nextious row
|
|
|
|
if (testing_on)
|
|
tprintf ("Row at %g(%g), dropout dist=%d,",
|
|
row->intercept (), row->parallel_c (), distance);
|
|
if (distance < 0) {
|
|
row_inc = 1;
|
|
abs_dist = -distance;
|
|
}
|
|
else {
|
|
row_inc = -1;
|
|
abs_dist = distance;
|
|
}
|
|
if (abs_dist > dist_limit) {
|
|
if (testing_on) {
|
|
tprintf (" too far - deleting\n");
|
|
}
|
|
return true;
|
|
}
|
|
if ((distance < 0 && !row_it->at_last ())
|
|
|| (distance >= 0 && !row_it->at_first ())) {
|
|
row_offset = row_inc;
|
|
do {
|
|
next_row = row_it->data_relative (row_offset);
|
|
next_index = (int32_t) floor (next_row->intercept ());
|
|
if ((distance < 0
|
|
&& next_index < line_index
|
|
&& next_index > line_index + distance + distance)
|
|
|| (distance >= 0
|
|
&& next_index > line_index
|
|
&& next_index < line_index + distance + distance)) {
|
|
if (testing_on) {
|
|
tprintf (" nearer neighbour (%d) at %g\n",
|
|
line_index + distance - next_index,
|
|
next_row->intercept ());
|
|
}
|
|
return true; //other is nearer
|
|
}
|
|
else if (next_index == line_index
|
|
|| next_index == line_index + distance + distance) {
|
|
if (row->believability () <= next_row->believability ()) {
|
|
if (testing_on) {
|
|
tprintf (" equal but more believable at %g (%g/%g)\n",
|
|
next_row->intercept (),
|
|
row->believability (),
|
|
next_row->believability ());
|
|
}
|
|
return true; //other is more believable
|
|
}
|
|
}
|
|
row_offset += row_inc;
|
|
}
|
|
while ((next_index == line_index
|
|
|| next_index == line_index + distance + distance)
|
|
&& row_offset < row_it->length ());
|
|
if (testing_on)
|
|
tprintf (" keeping\n");
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name deskew_block_coords
|
|
*
|
|
* Compute the bounding box of all the blobs in the block
|
|
* if they were deskewed without actually doing it.
|
|
*/
|
|
TBOX deskew_block_coords( //block box
|
|
TO_BLOCK *block, //block to do
|
|
float gradient //global skew
|
|
) {
|
|
TBOX result; //block bounds
|
|
TBOX blob_box; //of block
|
|
FCOORD rotation; //deskew vector
|
|
float length; //of gradient vector
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
TO_ROW *row; //current row
|
|
BLOBNBOX *blob; //current blob
|
|
BLOBNBOX_IT blob_it; //iterator
|
|
|
|
length = sqrt (gradient * gradient + 1);
|
|
rotation = FCOORD (1 / length, -gradient / length);
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
row = row_it.data ();
|
|
blob_it.set_to_list (row->blob_list ());
|
|
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
|
|
blob_it.forward ()) {
|
|
blob = blob_it.data ();
|
|
blob_box = blob->bounding_box ();
|
|
blob_box.rotate (rotation);//de-skew it
|
|
result += blob_box;
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name compute_line_occupation
|
|
*
|
|
* Compute the pixel projection back on the y axis given the global
|
|
* skew. Also compute the 1st derivative.
|
|
*/
|
|
void compute_line_occupation( //project blobs
|
|
TO_BLOCK *block, //block to do
|
|
float gradient, //global skew
|
|
int32_t min_y, //min coord in block
|
|
int32_t max_y, //in block
|
|
int32_t *occupation, //output projection
|
|
int32_t *deltas //derivative
|
|
) {
|
|
int32_t line_count; //maxy-miny+1
|
|
int32_t line_index; //of scan line
|
|
int index; //array index for daft compilers
|
|
TO_ROW *row; //current row
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
BLOBNBOX *blob; //current blob
|
|
BLOBNBOX_IT blob_it; //iterator
|
|
float length; //of skew vector
|
|
TBOX blob_box; //bounding box
|
|
FCOORD rotation; //inverse of skew
|
|
|
|
line_count = max_y - min_y + 1;
|
|
length = sqrt (gradient * gradient + 1);
|
|
rotation = FCOORD (1 / length, -gradient / length);
|
|
for (line_index = 0; line_index < line_count; line_index++)
|
|
deltas[line_index] = 0;
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
row = row_it.data ();
|
|
blob_it.set_to_list (row->blob_list ());
|
|
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
|
|
blob_it.forward ()) {
|
|
blob = blob_it.data ();
|
|
blob_box = blob->bounding_box ();
|
|
blob_box.rotate (rotation);//de-skew it
|
|
int32_t width = blob_box.right() - blob_box.left();
|
|
index = blob_box.bottom() - min_y;
|
|
ASSERT_HOST(index >= 0 && index < line_count);
|
|
// count transitions
|
|
deltas[index] += width;
|
|
index = blob_box.top() - min_y;
|
|
ASSERT_HOST(index >= 0 && index < line_count);
|
|
deltas[index] -= width;
|
|
}
|
|
}
|
|
occupation[0] = deltas[0];
|
|
for (line_index = 1; line_index < line_count; line_index++)
|
|
occupation[line_index] = occupation[line_index - 1] + deltas[line_index];
|
|
}
|
|
|
|
|
|
/**
|
|
* compute_occupation_threshold
|
|
*
|
|
* Compute thresholds for textline or not for the occupation array.
|
|
*/
|
|
void compute_occupation_threshold( //project blobs
|
|
int32_t low_window, //below result point
|
|
int32_t high_window, //above result point
|
|
int32_t line_count, //array sizes
|
|
int32_t *occupation, //input projection
|
|
int32_t *thresholds //output thresholds
|
|
) {
|
|
int32_t line_index; //of thresholds line
|
|
int32_t low_index; //in occupation
|
|
int32_t high_index; //in occupation
|
|
int32_t sum; //current average
|
|
int32_t divisor; //to get thresholds
|
|
int32_t min_index; //of min occ
|
|
int32_t min_occ; //min in locality
|
|
int32_t test_index; //for finding min
|
|
|
|
divisor =
|
|
(int32_t) ceil ((low_window + high_window) / textord_occupancy_threshold);
|
|
if (low_window + high_window < line_count) {
|
|
for (sum = 0, high_index = 0; high_index < low_window; high_index++)
|
|
sum += occupation[high_index];
|
|
for (low_index = 0; low_index < high_window; low_index++, high_index++)
|
|
sum += occupation[high_index];
|
|
min_occ = occupation[0];
|
|
min_index = 0;
|
|
for (test_index = 1; test_index < high_index; test_index++) {
|
|
if (occupation[test_index] <= min_occ) {
|
|
min_occ = occupation[test_index];
|
|
min_index = test_index; //find min in region
|
|
}
|
|
}
|
|
for (line_index = 0; line_index < low_window; line_index++)
|
|
thresholds[line_index] = (sum - min_occ) / divisor + min_occ;
|
|
//same out to end
|
|
for (low_index = 0; high_index < line_count; low_index++, high_index++) {
|
|
sum -= occupation[low_index];
|
|
sum += occupation[high_index];
|
|
if (occupation[high_index] <= min_occ) {
|
|
//find min in region
|
|
min_occ = occupation[high_index];
|
|
min_index = high_index;
|
|
}
|
|
//lost min from region
|
|
if (min_index <= low_index) {
|
|
min_occ = occupation[low_index + 1];
|
|
min_index = low_index + 1;
|
|
for (test_index = low_index + 2; test_index <= high_index;
|
|
test_index++) {
|
|
if (occupation[test_index] <= min_occ) {
|
|
min_occ = occupation[test_index];
|
|
//find min in region
|
|
min_index = test_index;
|
|
}
|
|
}
|
|
}
|
|
thresholds[line_index++] = (sum - min_occ) / divisor + min_occ;
|
|
}
|
|
}
|
|
else {
|
|
min_occ = occupation[0];
|
|
min_index = 0;
|
|
for (sum = 0, low_index = 0; low_index < line_count; low_index++) {
|
|
if (occupation[low_index] < min_occ) {
|
|
min_occ = occupation[low_index];
|
|
min_index = low_index;
|
|
}
|
|
sum += occupation[low_index];
|
|
}
|
|
line_index = 0;
|
|
}
|
|
for (; line_index < line_count; line_index++)
|
|
thresholds[line_index] = (sum - min_occ) / divisor + min_occ;
|
|
//same out to end
|
|
}
|
|
|
|
|
|
/**
|
|
* @name compute_dropout_distances
|
|
*
|
|
* Compute the distance from each coordinate to the nearest dropout.
|
|
*/
|
|
void compute_dropout_distances( //project blobs
|
|
int32_t *occupation, //input projection
|
|
int32_t *thresholds, //output thresholds
|
|
int32_t line_count //array sizes
|
|
) {
|
|
int32_t line_index; //of thresholds line
|
|
int32_t distance; //from prev dropout
|
|
int32_t next_dist; //to next dropout
|
|
int32_t back_index; //for back filling
|
|
int32_t prev_threshold; //before overwrite
|
|
|
|
distance = -line_count;
|
|
line_index = 0;
|
|
do {
|
|
do {
|
|
distance--;
|
|
prev_threshold = thresholds[line_index];
|
|
//distance from prev
|
|
thresholds[line_index] = distance;
|
|
line_index++;
|
|
}
|
|
while (line_index < line_count
|
|
&& (occupation[line_index] < thresholds[line_index]
|
|
|| occupation[line_index - 1] >= prev_threshold));
|
|
if (line_index < line_count) {
|
|
back_index = line_index - 1;
|
|
next_dist = 1;
|
|
while (next_dist < -distance && back_index >= 0) {
|
|
thresholds[back_index] = next_dist;
|
|
back_index--;
|
|
next_dist++;
|
|
distance++;
|
|
}
|
|
distance = 1;
|
|
}
|
|
}
|
|
while (line_index < line_count);
|
|
}
|
|
|
|
|
|
/**
|
|
* @name expand_rows
|
|
*
|
|
* Expand each row to the least of its allowed size and touching its
|
|
* neighbours. If the expansion would entirely swallow a neighbouring row
|
|
* then do so.
|
|
*/
|
|
void expand_rows( //find lines
|
|
ICOORD page_tr, //top right
|
|
TO_BLOCK* block, //block to do
|
|
float gradient, //gradient to fit
|
|
FCOORD rotation, //for drawing
|
|
int32_t block_edge, //edge of block
|
|
bool testing_on //correct orientation
|
|
) {
|
|
bool swallowed_row; //eaten a neighbour
|
|
float y_max, y_min; //new row limits
|
|
float y_bottom, y_top; //allowed limits
|
|
TO_ROW *test_row; //next row
|
|
TO_ROW *row; //current row
|
|
//iterators
|
|
BLOBNBOX_IT blob_it = &block->blobs;
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (textord_show_expanded_rows && testing_on) {
|
|
if (to_win == nullptr)
|
|
create_to_win(page_tr);
|
|
}
|
|
#endif
|
|
|
|
adjust_row_limits(block); //shift min,max.
|
|
if (textord_new_initial_xheight) {
|
|
if (block->get_rows ()->length () == 0)
|
|
return;
|
|
compute_row_stats(block, textord_show_expanded_rows && testing_on);
|
|
}
|
|
assign_blobs_to_rows (block, &gradient, 4, true, false, false);
|
|
//get real membership
|
|
if (block->get_rows ()->length () == 0)
|
|
return;
|
|
fit_parallel_rows(block,
|
|
gradient,
|
|
rotation,
|
|
block_edge,
|
|
textord_show_expanded_rows && testing_on);
|
|
if (!textord_new_initial_xheight)
|
|
compute_row_stats(block, textord_show_expanded_rows && testing_on);
|
|
row_it.move_to_last ();
|
|
do {
|
|
row = row_it.data ();
|
|
y_max = row->max_y (); //get current limits
|
|
y_min = row->min_y ();
|
|
y_bottom = row->intercept () - block->line_size * textord_expansion_factor *
|
|
tesseract::CCStruct::kDescenderFraction;
|
|
y_top = row->intercept () + block->line_size * textord_expansion_factor *
|
|
(tesseract::CCStruct::kXHeightFraction +
|
|
tesseract::CCStruct::kAscenderFraction);
|
|
if (y_min > y_bottom) { //expansion allowed
|
|
if (textord_show_expanded_rows && testing_on)
|
|
tprintf("Expanding bottom of row at %f from %f to %f\n",
|
|
row->intercept(), y_min, y_bottom);
|
|
//expandable
|
|
swallowed_row = true;
|
|
while (swallowed_row && !row_it.at_last ()) {
|
|
swallowed_row = false;
|
|
//get next one
|
|
test_row = row_it.data_relative (1);
|
|
//overlaps space
|
|
if (test_row->max_y () > y_bottom) {
|
|
if (test_row->min_y () > y_bottom) {
|
|
if (textord_show_expanded_rows && testing_on)
|
|
tprintf("Eating row below at %f\n", test_row->intercept());
|
|
row_it.forward ();
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (textord_show_expanded_rows && testing_on)
|
|
plot_parallel_row(test_row,
|
|
gradient,
|
|
block_edge,
|
|
ScrollView::WHITE,
|
|
rotation);
|
|
#endif
|
|
blob_it.set_to_list (row->blob_list ());
|
|
blob_it.add_list_after (test_row->blob_list ());
|
|
//swallow complete row
|
|
delete row_it.extract ();
|
|
row_it.backward ();
|
|
swallowed_row = true;
|
|
}
|
|
else if (test_row->max_y () < y_min) {
|
|
//shorter limit
|
|
y_bottom = test_row->max_y ();
|
|
if (textord_show_expanded_rows && testing_on)
|
|
tprintf("Truncating limit to %f due to touching row at %f\n",
|
|
y_bottom, test_row->intercept());
|
|
}
|
|
else {
|
|
y_bottom = y_min; //can't expand it
|
|
if (textord_show_expanded_rows && testing_on)
|
|
tprintf("Not expanding limit beyond %f due to touching row at %f\n",
|
|
y_bottom, test_row->intercept());
|
|
}
|
|
}
|
|
}
|
|
y_min = y_bottom; //expand it
|
|
}
|
|
if (y_max < y_top) { //expansion allowed
|
|
if (textord_show_expanded_rows && testing_on)
|
|
tprintf("Expanding top of row at %f from %f to %f\n",
|
|
row->intercept(), y_max, y_top);
|
|
swallowed_row = true;
|
|
while (swallowed_row && !row_it.at_first ()) {
|
|
swallowed_row = false;
|
|
//get one above
|
|
test_row = row_it.data_relative (-1);
|
|
if (test_row->min_y () < y_top) {
|
|
if (test_row->max_y () < y_top) {
|
|
if (textord_show_expanded_rows && testing_on)
|
|
tprintf("Eating row above at %f\n", test_row->intercept());
|
|
row_it.backward ();
|
|
blob_it.set_to_list (row->blob_list ());
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (textord_show_expanded_rows && testing_on)
|
|
plot_parallel_row(test_row,
|
|
gradient,
|
|
block_edge,
|
|
ScrollView::WHITE,
|
|
rotation);
|
|
#endif
|
|
blob_it.add_list_after (test_row->blob_list ());
|
|
//swallow complete row
|
|
delete row_it.extract ();
|
|
row_it.forward ();
|
|
swallowed_row = true;
|
|
}
|
|
else if (test_row->min_y () < y_max) {
|
|
//shorter limit
|
|
y_top = test_row->min_y ();
|
|
if (textord_show_expanded_rows && testing_on)
|
|
tprintf("Truncating limit to %f due to touching row at %f\n",
|
|
y_top, test_row->intercept());
|
|
}
|
|
else {
|
|
y_top = y_max; //can't expand it
|
|
if (textord_show_expanded_rows && testing_on)
|
|
tprintf("Not expanding limit beyond %f due to touching row at %f\n",
|
|
y_top, test_row->intercept());
|
|
}
|
|
}
|
|
}
|
|
y_max = y_top;
|
|
}
|
|
//new limits
|
|
row->set_limits (y_min, y_max);
|
|
row_it.backward ();
|
|
}
|
|
while (!row_it.at_last ());
|
|
}
|
|
|
|
|
|
/**
|
|
* adjust_row_limits
|
|
*
|
|
* Change the limits of rows to suit the default fractions.
|
|
*/
|
|
void adjust_row_limits( //tidy limits
|
|
TO_BLOCK *block //block to do
|
|
) {
|
|
TO_ROW *row; //current row
|
|
float size; //size of row
|
|
float ymax; //top of row
|
|
float ymin; //bottom of row
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
|
|
if (textord_show_expanded_rows)
|
|
tprintf("Adjusting row limits for block(%d,%d)\n",
|
|
block->block->pdblk.bounding_box().left(),
|
|
block->block->pdblk.bounding_box().top());
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
row = row_it.data ();
|
|
size = row->max_y () - row->min_y ();
|
|
if (textord_show_expanded_rows)
|
|
tprintf("Row at %f has min %f, max %f, size %f\n",
|
|
row->intercept(), row->min_y(), row->max_y(), size);
|
|
size /= tesseract::CCStruct::kXHeightFraction +
|
|
tesseract::CCStruct::kAscenderFraction +
|
|
tesseract::CCStruct::kDescenderFraction;
|
|
ymax = size * (tesseract::CCStruct::kXHeightFraction +
|
|
tesseract::CCStruct::kAscenderFraction);
|
|
ymin = -size * tesseract::CCStruct::kDescenderFraction;
|
|
row->set_limits (row->intercept () + ymin, row->intercept () + ymax);
|
|
row->merged = false;
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* @name compute_row_stats
|
|
*
|
|
* Compute the linespacing and offset.
|
|
*/
|
|
void compute_row_stats( //find lines
|
|
TO_BLOCK* block, //block to do
|
|
bool testing_on //correct orientation
|
|
) {
|
|
int32_t row_index; //of median
|
|
TO_ROW *row; //current row
|
|
TO_ROW *prev_row; //previous row
|
|
float iqr; //inter quartile range
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
//number of rows
|
|
int16_t rowcount = row_it.length ();
|
|
// for choose nth
|
|
std::vector<TO_ROW*> rows(rowcount);
|
|
rowcount = 0;
|
|
prev_row = nullptr;
|
|
row_it.move_to_last (); //start at bottom
|
|
do {
|
|
row = row_it.data ();
|
|
if (prev_row != nullptr) {
|
|
rows[rowcount++] = prev_row;
|
|
prev_row->spacing = row->intercept () - prev_row->intercept ();
|
|
if (testing_on)
|
|
tprintf ("Row at %g yields spacing of %g\n",
|
|
row->intercept (), prev_row->spacing);
|
|
}
|
|
prev_row = row;
|
|
row_it.backward ();
|
|
}
|
|
while (!row_it.at_last ());
|
|
block->key_row = prev_row;
|
|
block->baseline_offset =
|
|
fmod (prev_row->parallel_c (), block->line_spacing);
|
|
if (testing_on)
|
|
tprintf ("Blob based spacing=(%g,%g), offset=%g",
|
|
block->line_size, block->line_spacing, block->baseline_offset);
|
|
if (rowcount > 0) {
|
|
row_index = choose_nth_item(rowcount * 3 / 4, &rows[0], rowcount,
|
|
sizeof (TO_ROW *), row_spacing_order);
|
|
iqr = rows[row_index]->spacing;
|
|
row_index = choose_nth_item(rowcount / 4, &rows[0], rowcount,
|
|
sizeof (TO_ROW *), row_spacing_order);
|
|
iqr -= rows[row_index]->spacing;
|
|
row_index = choose_nth_item(rowcount / 2, &rows[0], rowcount,
|
|
sizeof (TO_ROW *), row_spacing_order);
|
|
block->key_row = rows[row_index];
|
|
if (testing_on)
|
|
tprintf (" row based=%g(%g)", rows[row_index]->spacing, iqr);
|
|
if (rowcount > 2
|
|
&& iqr < rows[row_index]->spacing * textord_linespace_iqrlimit) {
|
|
if (!textord_new_initial_xheight) {
|
|
if (rows[row_index]->spacing < block->line_spacing
|
|
&& rows[row_index]->spacing > block->line_size)
|
|
//within range
|
|
block->line_size = rows[row_index]->spacing;
|
|
//spacing=size
|
|
else if (rows[row_index]->spacing > block->line_spacing)
|
|
block->line_size = block->line_spacing;
|
|
//too big so use max
|
|
}
|
|
else {
|
|
if (rows[row_index]->spacing < block->line_spacing)
|
|
block->line_size = rows[row_index]->spacing;
|
|
else
|
|
block->line_size = block->line_spacing;
|
|
//too big so use max
|
|
}
|
|
if (block->line_size < textord_min_xheight)
|
|
block->line_size = (float) textord_min_xheight;
|
|
block->line_spacing = rows[row_index]->spacing;
|
|
block->max_blob_size =
|
|
block->line_spacing * textord_excess_blobsize;
|
|
}
|
|
block->baseline_offset = fmod (rows[row_index]->intercept (),
|
|
block->line_spacing);
|
|
}
|
|
if (testing_on)
|
|
tprintf ("\nEstimate line size=%g, spacing=%g, offset=%g\n",
|
|
block->line_size, block->line_spacing, block->baseline_offset);
|
|
}
|
|
|
|
|
|
/**
|
|
* @name compute_block_xheight
|
|
*
|
|
* Compute the xheight of the individual rows, then correlate them
|
|
* and interpret ascenderless lines, correcting xheights.
|
|
*
|
|
* First we compute our best guess of the x-height of each row independently
|
|
* with compute_row_xheight(), which looks for a pair of commonly occurring
|
|
* heights that could be x-height and ascender height. This function also
|
|
* attempts to find descenders of lowercase letters (i.e. not the small
|
|
* descenders that could appear in upper case letters as Q,J).
|
|
*
|
|
* After this computation each row falls into one of the following categories:
|
|
* ROW_ASCENDERS_FOUND: we found xheight and ascender modes, so this must be
|
|
* a regular row; we'll use its xheight to compute
|
|
* xheight and ascrise estimates for the block
|
|
* ROW_DESCENDERS_FOUND: no ascenders, so we do not have a high confidence in
|
|
* the xheight of this row (don't use it for estimating
|
|
* block xheight), but this row can't contain all caps
|
|
* ROW_UNKNOWN: a row with no ascenders/descenders, could be all lowercase
|
|
* (or mostly lowercase for fonts with very few ascenders),
|
|
* all upper case or small caps
|
|
* ROW_INVALID: no meaningful xheight could be found for this row
|
|
*
|
|
* We then run correct_row_xheight() and use the computed xheight and ascrise
|
|
* averages to correct xheight values of the rows in ROW_DESCENDERS_FOUND,
|
|
* ROW_UNKNOWN and ROW_INVALID categories.
|
|
*
|
|
*/
|
|
namespace tesseract {
|
|
void Textord::compute_block_xheight(TO_BLOCK *block, float gradient) {
|
|
TO_ROW *row; // current row
|
|
float asc_frac_xheight = CCStruct::kAscenderFraction /
|
|
CCStruct::kXHeightFraction;
|
|
float desc_frac_xheight = CCStruct::kDescenderFraction /
|
|
CCStruct::kXHeightFraction;
|
|
int32_t min_height, max_height; // limits on xheight
|
|
TO_ROW_IT row_it = block->get_rows();
|
|
if (row_it.empty()) return; // no rows
|
|
|
|
// Compute the best guess of xheight of each row individually.
|
|
// Use xheight and ascrise values of the rows where ascenders were found.
|
|
get_min_max_xheight(block->line_size, &min_height, &max_height);
|
|
STATS row_asc_xheights(min_height, max_height + 1);
|
|
STATS row_asc_ascrise(static_cast<int>(min_height * asc_frac_xheight),
|
|
static_cast<int>(max_height * asc_frac_xheight) + 1);
|
|
int min_desc_height = static_cast<int>(min_height * desc_frac_xheight);
|
|
int max_desc_height = static_cast<int>(max_height * desc_frac_xheight);
|
|
STATS row_asc_descdrop(min_desc_height, max_desc_height + 1);
|
|
STATS row_desc_xheights(min_height, max_height + 1);
|
|
STATS row_desc_descdrop(min_desc_height, max_desc_height + 1);
|
|
STATS row_cap_xheights(min_height, max_height + 1);
|
|
STATS row_cap_floating_xheights(min_height, max_height + 1);
|
|
for (row_it.mark_cycle_pt(); !row_it.cycled_list(); row_it.forward()) {
|
|
row = row_it.data();
|
|
// Compute the xheight of this row if it has not been computed before.
|
|
if (row->xheight <= 0.0) {
|
|
compute_row_xheight(row, block->block->classify_rotation(),
|
|
gradient, block->line_size);
|
|
}
|
|
ROW_CATEGORY row_category = get_row_category(row);
|
|
if (row_category == ROW_ASCENDERS_FOUND) {
|
|
row_asc_xheights.add(static_cast<int32_t>(row->xheight),
|
|
row->xheight_evidence);
|
|
row_asc_ascrise.add(static_cast<int32_t>(row->ascrise),
|
|
row->xheight_evidence);
|
|
row_asc_descdrop.add(static_cast<int32_t>(-row->descdrop),
|
|
row->xheight_evidence);
|
|
} else if (row_category == ROW_DESCENDERS_FOUND) {
|
|
row_desc_xheights.add(static_cast<int32_t>(row->xheight),
|
|
row->xheight_evidence);
|
|
row_desc_descdrop.add(static_cast<int32_t>(-row->descdrop),
|
|
row->xheight_evidence);
|
|
} else if (row_category == ROW_UNKNOWN) {
|
|
fill_heights(row, gradient, min_height, max_height,
|
|
&row_cap_xheights, &row_cap_floating_xheights);
|
|
}
|
|
}
|
|
|
|
float xheight = 0.0;
|
|
float ascrise = 0.0;
|
|
float descdrop = 0.0;
|
|
// Compute our best guess of xheight of this block.
|
|
if (row_asc_xheights.get_total() > 0) {
|
|
// Determine xheight from rows where ascenders were found.
|
|
xheight = row_asc_xheights.median();
|
|
ascrise = row_asc_ascrise.median();
|
|
descdrop = -row_asc_descdrop.median();
|
|
} else if (row_desc_xheights.get_total() > 0) {
|
|
// Determine xheight from rows where descenders were found.
|
|
xheight = row_desc_xheights.median();
|
|
descdrop = -row_desc_descdrop.median();
|
|
} else if (row_cap_xheights.get_total() > 0) {
|
|
// All the rows in the block were (a/de)scenderless.
|
|
// Try to search for two modes in row_cap_heights that could
|
|
// be the xheight and the capheight (e.g. some of the rows
|
|
// were lowercase, but did not have enough (a/de)scenders.
|
|
// If such two modes can not be found, this block is most
|
|
// likely all caps (or all small caps, in which case the code
|
|
// still works as intended).
|
|
compute_xheight_from_modes(&row_cap_xheights, &row_cap_floating_xheights,
|
|
textord_single_height_mode &&
|
|
block->block->classify_rotation().y() == 0.0,
|
|
min_height, max_height, &(xheight), &(ascrise));
|
|
if (ascrise == 0) { // assume only caps in the whole block
|
|
xheight = row_cap_xheights.median() * CCStruct::kXHeightCapRatio;
|
|
}
|
|
} else { // default block sizes
|
|
xheight = block->line_size * CCStruct::kXHeightFraction;
|
|
}
|
|
// Correct xheight, ascrise and descdrop if necessary.
|
|
bool corrected_xheight = false;
|
|
if (xheight < textord_min_xheight) {
|
|
xheight = static_cast<float>(textord_min_xheight);
|
|
corrected_xheight = true;
|
|
}
|
|
if (corrected_xheight || ascrise <= 0.0) {
|
|
ascrise = xheight * asc_frac_xheight;
|
|
}
|
|
if (corrected_xheight || descdrop >= 0.0) {
|
|
descdrop = -(xheight * desc_frac_xheight);
|
|
}
|
|
block->xheight = xheight;
|
|
|
|
if (textord_debug_xheights) {
|
|
tprintf("Block average xheight=%.4f, ascrise=%.4f, descdrop=%.4f\n",
|
|
xheight, ascrise, descdrop);
|
|
}
|
|
// Correct xheight, ascrise, descdrop of rows based on block averages.
|
|
for (row_it.mark_cycle_pt(); !row_it.cycled_list(); row_it.forward()) {
|
|
correct_row_xheight(row_it.data(), xheight, ascrise, descdrop);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @name compute_row_xheight
|
|
*
|
|
* Estimate the xheight of this row.
|
|
* Compute the ascender rise and descender drop at the same time.
|
|
* Set xheigh_evidence to the number of blobs with the chosen xheight
|
|
* that appear in this row.
|
|
*/
|
|
void Textord::compute_row_xheight(TO_ROW *row, // row to do
|
|
const FCOORD& rotation,
|
|
float gradient, // global skew
|
|
int block_line_size) {
|
|
// Find blobs representing repeated characters in rows and mark them.
|
|
// This information is used for computing row xheight and at a later
|
|
// stage when words are formed by make_words.
|
|
if (!row->rep_chars_marked()) {
|
|
mark_repeated_chars(row);
|
|
}
|
|
|
|
int min_height, max_height;
|
|
get_min_max_xheight(block_line_size, &min_height, &max_height);
|
|
STATS heights(min_height, max_height + 1);
|
|
STATS floating_heights(min_height, max_height + 1);
|
|
fill_heights(row, gradient, min_height, max_height,
|
|
&heights, &floating_heights);
|
|
row->ascrise = 0.0f;
|
|
row->xheight = 0.0f;
|
|
row->xheight_evidence =
|
|
compute_xheight_from_modes(&heights, &floating_heights,
|
|
textord_single_height_mode &&
|
|
rotation.y() == 0.0,
|
|
min_height, max_height,
|
|
&(row->xheight), &(row->ascrise));
|
|
row->descdrop = 0.0f;
|
|
if (row->xheight > 0.0) {
|
|
row->descdrop = static_cast<float>(
|
|
compute_row_descdrop(row, gradient, row->xheight_evidence, &heights));
|
|
}
|
|
}
|
|
|
|
} // namespace tesseract.
|
|
|
|
/**
|
|
* @name fill_heights
|
|
*
|
|
* Fill the given heights with heights of the blobs that are legal
|
|
* candidates for estimating xheight.
|
|
*/
|
|
void fill_heights(TO_ROW *row, float gradient, int min_height,
|
|
int max_height, STATS *heights, STATS *floating_heights) {
|
|
float xcentre; // centre of blob
|
|
float top; // top y coord of blob
|
|
float height; // height of blob
|
|
BLOBNBOX *blob; // current blob
|
|
int repeated_set;
|
|
BLOBNBOX_IT blob_it = row->blob_list();
|
|
if (blob_it.empty()) return; // no blobs in this row
|
|
bool has_rep_chars =
|
|
row->rep_chars_marked() && row->num_repeated_sets() > 0;
|
|
do {
|
|
blob = blob_it.data();
|
|
if (!blob->joined_to_prev()) {
|
|
xcentre = (blob->bounding_box().left() +
|
|
blob->bounding_box().right()) / 2.0f;
|
|
top = blob->bounding_box().top();
|
|
height = blob->bounding_box().height();
|
|
if (textord_fix_xheight_bug)
|
|
top -= row->baseline.y(xcentre);
|
|
else
|
|
top -= gradient * xcentre + row->parallel_c();
|
|
if (top >= min_height && top <= max_height) {
|
|
heights->add(static_cast<int32_t>(floor(top + 0.5)), 1);
|
|
if (height / top < textord_min_blob_height_fraction) {
|
|
floating_heights->add(static_cast<int32_t>(floor(top + 0.5)), 1);
|
|
}
|
|
}
|
|
}
|
|
// Skip repeated chars, since they are likely to skew the height stats.
|
|
if (has_rep_chars && blob->repeated_set() != 0) {
|
|
repeated_set = blob->repeated_set();
|
|
blob_it.forward();
|
|
while (!blob_it.at_first() &&
|
|
blob_it.data()->repeated_set() == repeated_set) {
|
|
blob_it.forward();
|
|
if (textord_debug_xheights)
|
|
tprintf("Skipping repeated char when computing xheight\n");
|
|
}
|
|
} else {
|
|
blob_it.forward();
|
|
}
|
|
} while (!blob_it.at_first());
|
|
}
|
|
|
|
/**
|
|
* @name compute_xheight_from_modes
|
|
*
|
|
* Given a STATS object heights, looks for two most frequently occurring
|
|
* heights that look like xheight and xheight + ascrise. If found, sets
|
|
* the values of *xheight and *ascrise accordingly, otherwise sets xheight
|
|
* to any most frequently occurring height and sets *ascrise to 0.
|
|
* Returns the number of times xheight occurred in heights.
|
|
* For each mode that is considered for being an xheight the count of
|
|
* floating blobs (stored in floating_heights) is subtracted from the
|
|
* total count of the blobs of this height. This is done because blobs
|
|
* that sit far above the baseline could represent valid ascenders, but
|
|
* it is highly unlikely that such a character's height will be an xheight
|
|
* (e.g. -, ', =, ^, `, ", ', etc)
|
|
* If cap_only, then force finding of only the top mode.
|
|
*/
|
|
int compute_xheight_from_modes(
|
|
STATS *heights, STATS *floating_heights, bool cap_only, int min_height,
|
|
int max_height, float *xheight, float *ascrise) {
|
|
int blob_index = heights->mode(); // find mode
|
|
int blob_count = heights->pile_count(blob_index); // get count of mode
|
|
if (textord_debug_xheights) {
|
|
tprintf("min_height=%d, max_height=%d, mode=%d, count=%d, total=%d\n",
|
|
min_height, max_height, blob_index, blob_count,
|
|
heights->get_total());
|
|
heights->print();
|
|
floating_heights->print();
|
|
}
|
|
if (blob_count == 0) return 0;
|
|
int modes[MAX_HEIGHT_MODES]; // biggest piles
|
|
bool in_best_pile = FALSE;
|
|
int prev_size = -INT32_MAX;
|
|
int best_count = 0;
|
|
int mode_count = compute_height_modes(heights, min_height, max_height,
|
|
modes, MAX_HEIGHT_MODES);
|
|
if (cap_only && mode_count > 1)
|
|
mode_count = 1;
|
|
int x;
|
|
if (textord_debug_xheights) {
|
|
tprintf("found %d modes: ", mode_count);
|
|
for (x = 0; x < mode_count; x++) tprintf("%d ", modes[x]);
|
|
tprintf("\n");
|
|
}
|
|
|
|
for (x = 0; x < mode_count - 1; x++) {
|
|
if (modes[x] != prev_size + 1)
|
|
in_best_pile = FALSE; // had empty height
|
|
int modes_x_count = heights->pile_count(modes[x]) -
|
|
floating_heights->pile_count(modes[x]);
|
|
if ((modes_x_count >= blob_count * textord_xheight_mode_fraction) &&
|
|
(in_best_pile || modes_x_count > best_count)) {
|
|
for (int asc = x + 1; asc < mode_count; asc++) {
|
|
float ratio =
|
|
static_cast<float>(modes[asc]) / static_cast<float>(modes[x]);
|
|
if (textord_ascx_ratio_min < ratio &&
|
|
ratio < textord_ascx_ratio_max &&
|
|
(heights->pile_count(modes[asc]) >=
|
|
blob_count * textord_ascheight_mode_fraction)) {
|
|
if (modes_x_count > best_count) {
|
|
in_best_pile = true;
|
|
best_count = modes_x_count;
|
|
}
|
|
if (textord_debug_xheights) {
|
|
tprintf("X=%d, asc=%d, count=%d, ratio=%g\n",
|
|
modes[x], modes[asc]-modes[x], modes_x_count, ratio);
|
|
}
|
|
prev_size = modes[x];
|
|
*xheight = static_cast<float>(modes[x]);
|
|
*ascrise = static_cast<float>(modes[asc] - modes[x]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (*xheight == 0) { // single mode
|
|
// Remove counts of the "floating" blobs (the one whose height is too
|
|
// small in relation to it's top end of the bounding box) from heights
|
|
// before computing the single-mode xheight.
|
|
// Restore the counts in heights after the mode is found, since
|
|
// floating blobs might be useful for determining potential ascenders
|
|
// in compute_row_descdrop().
|
|
if (floating_heights->get_total() > 0) {
|
|
for (x = min_height; x < max_height; ++x) {
|
|
heights->add(x, -(floating_heights->pile_count(x)));
|
|
}
|
|
blob_index = heights->mode(); // find the modified mode
|
|
for (x = min_height; x < max_height; ++x) {
|
|
heights->add(x, floating_heights->pile_count(x));
|
|
}
|
|
}
|
|
*xheight = static_cast<float>(blob_index);
|
|
*ascrise = 0.0f;
|
|
best_count = heights->pile_count(blob_index);
|
|
if (textord_debug_xheights)
|
|
tprintf("Single mode xheight set to %g\n", *xheight);
|
|
} else if (textord_debug_xheights) {
|
|
tprintf("Multi-mode xheight set to %g, asc=%g\n", *xheight, *ascrise);
|
|
}
|
|
return best_count;
|
|
}
|
|
|
|
/**
|
|
* @name compute_row_descdrop
|
|
*
|
|
* Estimates the descdrop of this row. This function looks for
|
|
* "significant" descenders of lowercase letters (those that could
|
|
* not just be the small descenders of upper case letters like Q,J).
|
|
* The function also takes into account how many potential ascenders
|
|
* this row might contain. If the number of potential ascenders along
|
|
* with descenders is close to the expected fraction of the total
|
|
* number of blobs in the row, the function returns the descender
|
|
* height, returns 0 otherwise.
|
|
*/
|
|
int32_t compute_row_descdrop(TO_ROW *row, float gradient,
|
|
int xheight_blob_count, STATS *asc_heights) {
|
|
// Count how many potential ascenders are in this row.
|
|
int i_min = asc_heights->min_bucket();
|
|
if ((i_min / row->xheight) < textord_ascx_ratio_min) {
|
|
i_min = static_cast<int>(
|
|
floor(row->xheight * textord_ascx_ratio_min + 0.5));
|
|
}
|
|
int i_max = asc_heights->max_bucket();
|
|
if ((i_max / row->xheight) > textord_ascx_ratio_max) {
|
|
i_max = static_cast<int>(floor(row->xheight * textord_ascx_ratio_max));
|
|
}
|
|
int num_potential_asc = 0;
|
|
for (int i = i_min; i <= i_max; ++i) {
|
|
num_potential_asc += asc_heights->pile_count(i);
|
|
}
|
|
int32_t min_height =
|
|
static_cast<int32_t>(floor(row->xheight * textord_descx_ratio_min + 0.5));
|
|
int32_t max_height =
|
|
static_cast<int32_t>(floor(row->xheight * textord_descx_ratio_max));
|
|
float xcentre; // centre of blob
|
|
float height; // height of blob
|
|
BLOBNBOX_IT blob_it = row->blob_list();
|
|
BLOBNBOX *blob; // current blob
|
|
STATS heights (min_height, max_height + 1);
|
|
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
|
|
blob = blob_it.data();
|
|
if (!blob->joined_to_prev()) {
|
|
xcentre = (blob->bounding_box().left() +
|
|
blob->bounding_box().right()) / 2.0f;
|
|
height = (gradient * xcentre + row->parallel_c() -
|
|
blob->bounding_box().bottom());
|
|
if (height >= min_height && height <= max_height)
|
|
heights.add(static_cast<int>(floor(height + 0.5)), 1);
|
|
}
|
|
}
|
|
int blob_index = heights.mode(); // find mode
|
|
int blob_count = heights.pile_count(blob_index); // get count of mode
|
|
float total_fraction =
|
|
(textord_descheight_mode_fraction + textord_ascheight_mode_fraction);
|
|
if (static_cast<float>(blob_count + num_potential_asc) <
|
|
xheight_blob_count * total_fraction) {
|
|
blob_count = 0;
|
|
}
|
|
int descdrop = blob_count > 0 ? -blob_index : 0;
|
|
if (textord_debug_xheights) {
|
|
tprintf("Descdrop: %d (potential ascenders %d, descenders %d)\n",
|
|
descdrop, num_potential_asc, blob_count);
|
|
heights.print();
|
|
}
|
|
return descdrop;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name compute_height_modes
|
|
*
|
|
* Find the top maxmodes values in the input array and put their
|
|
* indices in the output in the order in which they occurred.
|
|
*/
|
|
int32_t compute_height_modes(STATS *heights, // stats to search
|
|
int32_t min_height, // bottom of range
|
|
int32_t max_height, // top of range
|
|
int32_t *modes, // output array
|
|
int32_t maxmodes) { // size of modes
|
|
int32_t pile_count; // no in source pile
|
|
int32_t src_count; // no of source entries
|
|
int32_t src_index; // current entry
|
|
int32_t least_count; // height of smalllest
|
|
int32_t least_index; // index of least
|
|
int32_t dest_count; // index in modes
|
|
|
|
src_count = max_height + 1 - min_height;
|
|
dest_count = 0;
|
|
least_count = INT32_MAX;
|
|
least_index = -1;
|
|
for (src_index = 0; src_index < src_count; src_index++) {
|
|
pile_count = heights->pile_count(min_height + src_index);
|
|
if (pile_count > 0) {
|
|
if (dest_count < maxmodes) {
|
|
if (pile_count < least_count) {
|
|
// find smallest in array
|
|
least_count = pile_count;
|
|
least_index = dest_count;
|
|
}
|
|
modes[dest_count++] = min_height + src_index;
|
|
} else if (pile_count >= least_count) {
|
|
while (least_index < maxmodes - 1) {
|
|
modes[least_index] = modes[least_index + 1];
|
|
// shuffle up
|
|
least_index++;
|
|
}
|
|
// new one on end
|
|
modes[maxmodes - 1] = min_height + src_index;
|
|
if (pile_count == least_count) {
|
|
// new smallest
|
|
least_index = maxmodes - 1;
|
|
} else {
|
|
least_count = heights->pile_count(modes[0]);
|
|
least_index = 0;
|
|
for (dest_count = 1; dest_count < maxmodes; dest_count++) {
|
|
pile_count = heights->pile_count(modes[dest_count]);
|
|
if (pile_count < least_count) {
|
|
// find smallest
|
|
least_count = pile_count;
|
|
least_index = dest_count;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return dest_count;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name correct_row_xheight
|
|
*
|
|
* Adjust the xheight etc of this row if not within reasonable limits
|
|
* of the average for the block.
|
|
*/
|
|
void correct_row_xheight(TO_ROW *row, float xheight,
|
|
float ascrise, float descdrop) {
|
|
ROW_CATEGORY row_category = get_row_category(row);
|
|
if (textord_debug_xheights) {
|
|
tprintf("correcting row xheight: row->xheight %.4f"
|
|
", row->acrise %.4f row->descdrop %.4f\n",
|
|
row->xheight, row->ascrise, row->descdrop);
|
|
}
|
|
bool normal_xheight =
|
|
within_error_margin(row->xheight, xheight, textord_xheight_error_margin);
|
|
bool cap_xheight =
|
|
within_error_margin(row->xheight, xheight + ascrise,
|
|
textord_xheight_error_margin);
|
|
// Use the average xheight/ascrise for the following cases:
|
|
// -- the xheight of the row could not be determined at all
|
|
// -- the row has descenders (e.g. "many groups", "ISBN 12345 p.3")
|
|
// and its xheight is close to either cap height or average xheight
|
|
// -- the row does not have ascenders or descenders, but its xheight
|
|
// is close to the average block xheight (e.g. row with "www.mmm.com")
|
|
if (row_category == ROW_ASCENDERS_FOUND) {
|
|
if (row->descdrop >= 0.0) {
|
|
row->descdrop = row->xheight * (descdrop / xheight);
|
|
}
|
|
} else if (row_category == ROW_INVALID ||
|
|
(row_category == ROW_DESCENDERS_FOUND &&
|
|
(normal_xheight || cap_xheight)) ||
|
|
(row_category == ROW_UNKNOWN && normal_xheight)) {
|
|
if (textord_debug_xheights) tprintf("using average xheight\n");
|
|
row->xheight = xheight;
|
|
row->ascrise = ascrise;
|
|
row->descdrop = descdrop;
|
|
} else if (row_category == ROW_DESCENDERS_FOUND) {
|
|
// Assume this is a row with mostly lowercase letters and it's xheight
|
|
// is computed correctly (unfortunately there is no way to distinguish
|
|
// this from the case when descenders are found, but the most common
|
|
// height is capheight).
|
|
if (textord_debug_xheights) tprintf("lowercase, corrected ascrise\n");
|
|
row->ascrise = row->xheight * (ascrise / xheight);
|
|
} else if (row_category == ROW_UNKNOWN) {
|
|
// Otherwise assume this row is an all-caps or small-caps row
|
|
// and adjust xheight and ascrise of the row.
|
|
|
|
row->all_caps = true;
|
|
if (cap_xheight) { // regular all caps
|
|
if (textord_debug_xheights) tprintf("all caps\n");
|
|
row->xheight = xheight;
|
|
row->ascrise = ascrise;
|
|
row->descdrop = descdrop;
|
|
} else { // small caps or caps with an odd xheight
|
|
if (textord_debug_xheights) {
|
|
if (row->xheight < xheight + ascrise && row->xheight > xheight) {
|
|
tprintf("small caps\n");
|
|
} else {
|
|
tprintf("all caps with irregular xheight\n");
|
|
}
|
|
}
|
|
row->ascrise = row->xheight * (ascrise / (xheight + ascrise));
|
|
row->xheight -= row->ascrise;
|
|
row->descdrop = row->xheight * (descdrop / xheight);
|
|
}
|
|
}
|
|
if (textord_debug_xheights) {
|
|
tprintf("corrected row->xheight = %.4f, row->acrise = %.4f, row->descdrop"
|
|
" = %.4f\n", row->xheight, row->ascrise, row->descdrop);
|
|
}
|
|
}
|
|
|
|
static int CountOverlaps(const TBOX& box, int min_height,
|
|
BLOBNBOX_LIST* blobs) {
|
|
int overlaps = 0;
|
|
BLOBNBOX_IT blob_it(blobs);
|
|
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
|
|
BLOBNBOX* blob = blob_it.data();
|
|
const TBOX &blob_box = blob->bounding_box();
|
|
if (blob_box.height() >= min_height && box.major_overlap(blob_box)) {
|
|
++overlaps;
|
|
}
|
|
}
|
|
return overlaps;
|
|
}
|
|
|
|
/**
|
|
* @name separate_underlines
|
|
*
|
|
* Test wide objects for being potential underlines. If they are then
|
|
* put them in a separate list in the block.
|
|
*/
|
|
void separate_underlines(TO_BLOCK* block, // block to do
|
|
float gradient, // skew angle
|
|
FCOORD rotation, // inverse landscape
|
|
bool testing_on) { // correct orientation
|
|
BLOBNBOX *blob; // current blob
|
|
C_BLOB *rotated_blob; // rotated blob
|
|
TO_ROW *row; // current row
|
|
float length; // of g_vec
|
|
TBOX blob_box;
|
|
FCOORD blob_rotation; // inverse of rotation
|
|
FCOORD g_vec; // skew rotation
|
|
BLOBNBOX_IT blob_it; // iterator
|
|
// iterator
|
|
BLOBNBOX_IT under_it = &block->underlines;
|
|
BLOBNBOX_IT large_it = &block->large_blobs;
|
|
TO_ROW_IT row_it = block->get_rows();
|
|
int min_blob_height = static_cast<int>(textord_min_blob_height_fraction *
|
|
block->line_size + 0.5);
|
|
|
|
// length of vector
|
|
length = sqrt(1 + gradient * gradient);
|
|
g_vec = FCOORD(1 / length, -gradient / length);
|
|
blob_rotation = FCOORD(rotation.x(), -rotation.y());
|
|
blob_rotation.rotate(g_vec); // undoing everything
|
|
for (row_it.mark_cycle_pt(); !row_it.cycled_list(); row_it.forward()) {
|
|
row = row_it.data();
|
|
// get blobs
|
|
blob_it.set_to_list(row->blob_list());
|
|
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list();
|
|
blob_it.forward()) {
|
|
blob = blob_it.data();
|
|
blob_box = blob->bounding_box();
|
|
if (blob_box.width() > block->line_size * textord_underline_width) {
|
|
ASSERT_HOST(blob->cblob() != nullptr);
|
|
rotated_blob = crotate_cblob (blob->cblob(),
|
|
blob_rotation);
|
|
if (test_underline(
|
|
testing_on && textord_show_final_rows,
|
|
rotated_blob, static_cast<int16_t>(row->intercept()),
|
|
static_cast<int16_t>(
|
|
block->line_size *
|
|
(tesseract::CCStruct::kXHeightFraction +
|
|
tesseract::CCStruct::kAscenderFraction / 2.0f)))) {
|
|
under_it.add_after_then_move(blob_it.extract());
|
|
if (testing_on && textord_show_final_rows) {
|
|
tprintf("Underlined blob at:");
|
|
rotated_blob->bounding_box().print();
|
|
tprintf("Was:");
|
|
blob_box.print();
|
|
}
|
|
} else if (CountOverlaps(blob->bounding_box(), min_blob_height,
|
|
row->blob_list()) >
|
|
textord_max_blob_overlaps) {
|
|
large_it.add_after_then_move(blob_it.extract());
|
|
if (testing_on && textord_show_final_rows) {
|
|
tprintf("Large blob overlaps %d blobs at:",
|
|
CountOverlaps(blob_box, min_blob_height,
|
|
row->blob_list()));
|
|
blob_box.print();
|
|
}
|
|
}
|
|
delete rotated_blob;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* @name pre_associate_blobs
|
|
*
|
|
* Associate overlapping blobs and fake chop wide blobs.
|
|
*/
|
|
void pre_associate_blobs( //make rough chars
|
|
ICOORD page_tr, //top right
|
|
TO_BLOCK* block, //block to do
|
|
FCOORD rotation, //inverse landscape
|
|
bool testing_on //correct orientation
|
|
) {
|
|
#ifndef GRAPHICS_DISABLED
|
|
ScrollView::Color colour; //of boxes
|
|
#endif
|
|
BLOBNBOX *blob; //current blob
|
|
BLOBNBOX *nextblob; //next in list
|
|
TBOX blob_box;
|
|
FCOORD blob_rotation; //inverse of rotation
|
|
BLOBNBOX_IT blob_it; //iterator
|
|
BLOBNBOX_IT start_it; //iterator
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
|
|
#ifndef GRAPHICS_DISABLED
|
|
colour = ScrollView::RED;
|
|
#endif
|
|
|
|
blob_rotation = FCOORD (rotation.x (), -rotation.y ());
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
//get blobs
|
|
blob_it.set_to_list (row_it.data ()->blob_list ());
|
|
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
|
|
blob_it.forward ()) {
|
|
blob = blob_it.data ();
|
|
blob_box = blob->bounding_box ();
|
|
start_it = blob_it; //save start point
|
|
// if (testing_on && textord_show_final_blobs)
|
|
// {
|
|
// tprintf("Blob at (%d,%d)->(%d,%d), addr=%x, count=%d\n",
|
|
// blob_box.left(),blob_box.bottom(),
|
|
// blob_box.right(),blob_box.top(),
|
|
// (void*)blob,blob_it.length());
|
|
// }
|
|
bool overlap;
|
|
do {
|
|
overlap = false;
|
|
if (!blob_it.at_last ()) {
|
|
nextblob = blob_it.data_relative(1);
|
|
overlap = blob_box.major_x_overlap(nextblob->bounding_box());
|
|
if (overlap) {
|
|
blob->merge(nextblob); // merge new blob
|
|
blob_box = blob->bounding_box(); // get bigger box
|
|
blob_it.forward();
|
|
}
|
|
}
|
|
}
|
|
while (overlap);
|
|
blob->chop (&start_it, &blob_it,
|
|
blob_rotation,
|
|
block->line_size * tesseract::CCStruct::kXHeightFraction *
|
|
textord_chop_width);
|
|
//attempt chop
|
|
}
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (testing_on && textord_show_final_blobs) {
|
|
if (to_win == nullptr)
|
|
create_to_win(page_tr);
|
|
to_win->Pen(colour);
|
|
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list ();
|
|
blob_it.forward ()) {
|
|
blob = blob_it.data ();
|
|
blob_box = blob->bounding_box ();
|
|
blob_box.rotate (rotation);
|
|
if (!blob->joined_to_prev ()) {
|
|
to_win->Rectangle (blob_box.left (), blob_box.bottom (),
|
|
blob_box.right (), blob_box.top ());
|
|
}
|
|
}
|
|
colour = (ScrollView::Color) (colour + 1);
|
|
if (colour > ScrollView::MAGENTA)
|
|
colour = ScrollView::RED;
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* @name fit_parallel_rows
|
|
*
|
|
* Re-fit the rows in the block to the given gradient.
|
|
*/
|
|
void fit_parallel_rows( //find lines
|
|
TO_BLOCK* block, //block to do
|
|
float gradient, //gradient to fit
|
|
FCOORD rotation, //for drawing
|
|
int32_t block_edge, //edge of block
|
|
bool testing_on //correct orientation
|
|
) {
|
|
#ifndef GRAPHICS_DISABLED
|
|
ScrollView::Color colour; //of row
|
|
#endif
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
|
|
row_it.move_to_first ();
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
if (row_it.data ()->blob_list ()->empty ())
|
|
delete row_it.extract (); //nothing in it
|
|
else
|
|
fit_parallel_lms (gradient, row_it.data ());
|
|
}
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (testing_on) {
|
|
colour = ScrollView::RED;
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
plot_parallel_row (row_it.data (), gradient,
|
|
block_edge, colour, rotation);
|
|
colour = (ScrollView::Color) (colour + 1);
|
|
if (colour > ScrollView::MAGENTA)
|
|
colour = ScrollView::RED;
|
|
}
|
|
}
|
|
#endif
|
|
row_it.sort (row_y_order); //may have gone out of order
|
|
}
|
|
|
|
|
|
/**
|
|
* @name fit_parallel_lms
|
|
*
|
|
* Fit an LMS line to a row.
|
|
* Make the fit parallel to the given gradient and set the
|
|
* row accordingly.
|
|
*/
|
|
void fit_parallel_lms(float gradient, TO_ROW *row) {
|
|
float c; // fitted line
|
|
int blobcount; // no of blobs
|
|
tesseract::DetLineFit lms;
|
|
BLOBNBOX_IT blob_it = row->blob_list();
|
|
|
|
blobcount = 0;
|
|
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
|
|
if (!blob_it.data()->joined_to_prev()) {
|
|
const TBOX& box = blob_it.data()->bounding_box();
|
|
lms.Add(ICOORD((box.left() + box.right()) / 2, box.bottom()));
|
|
blobcount++;
|
|
}
|
|
}
|
|
double error = lms.ConstrainedFit(gradient, &c);
|
|
row->set_parallel_line(gradient, c, error);
|
|
if (textord_straight_baselines && blobcount > textord_lms_line_trials) {
|
|
error = lms.Fit(&gradient, &c);
|
|
}
|
|
//set the other too
|
|
row->set_line(gradient, c, error);
|
|
}
|
|
|
|
|
|
/**
|
|
* @name make_spline_rows
|
|
*
|
|
* Re-fit the rows in the block to the given gradient.
|
|
*/
|
|
namespace tesseract {
|
|
void Textord::make_spline_rows(TO_BLOCK* block, // block to do
|
|
float gradient, // gradient to fit
|
|
bool testing_on) {
|
|
#ifndef GRAPHICS_DISABLED
|
|
ScrollView::Color colour; //of row
|
|
#endif
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
|
|
row_it.move_to_first ();
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
if (row_it.data ()->blob_list ()->empty ())
|
|
delete row_it.extract (); //nothing in it
|
|
else
|
|
make_baseline_spline (row_it.data (), block);
|
|
}
|
|
if (textord_old_baselines) {
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (testing_on) {
|
|
colour = ScrollView::RED;
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list ();
|
|
row_it.forward ()) {
|
|
row_it.data ()->baseline.plot (to_win, colour);
|
|
colour = (ScrollView::Color) (colour + 1);
|
|
if (colour > ScrollView::MAGENTA)
|
|
colour = ScrollView::RED;
|
|
}
|
|
}
|
|
#endif
|
|
make_old_baselines(block, testing_on, gradient);
|
|
}
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (testing_on) {
|
|
colour = ScrollView::RED;
|
|
for (row_it.mark_cycle_pt (); !row_it.cycled_list (); row_it.forward ()) {
|
|
row_it.data ()->baseline.plot (to_win, colour);
|
|
colour = (ScrollView::Color) (colour + 1);
|
|
if (colour > ScrollView::MAGENTA)
|
|
colour = ScrollView::RED;
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
|
|
} // namespace tesseract.
|
|
|
|
|
|
/**
|
|
* @name make_baseline_spline
|
|
*
|
|
* Fit an LMS line to a row.
|
|
* Make the fit parallel to the given gradient and set the
|
|
* row accordingly.
|
|
*/
|
|
void make_baseline_spline(TO_ROW *row, //row to fit
|
|
TO_BLOCK *block) {
|
|
double *coeffs; // quadratic coeffs
|
|
int32_t segments; // no of segments
|
|
|
|
// spline boundaries
|
|
int32_t *xstarts = new int32_t[row->blob_list()->length() + 1];
|
|
if (segment_baseline(row, block, segments, xstarts)
|
|
&& !textord_straight_baselines && !textord_parallel_baselines) {
|
|
coeffs = linear_spline_baseline(row, block, segments, xstarts);
|
|
} else {
|
|
xstarts[1] = xstarts[segments];
|
|
segments = 1;
|
|
coeffs = new double[3];
|
|
coeffs[0] = 0;
|
|
coeffs[1] = row->line_m ();
|
|
coeffs[2] = row->line_c ();
|
|
}
|
|
row->baseline = QSPLINE (segments, xstarts, coeffs);
|
|
delete[] coeffs;
|
|
delete[] xstarts;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name segment_baseline
|
|
*
|
|
* Divide the baseline up into segments which require a different
|
|
* quadratic fitted to them.
|
|
* Return TRUE if enough blobs were far enough away to need a quadratic.
|
|
*/
|
|
bool
|
|
segment_baseline( //split baseline
|
|
TO_ROW* row, //row to fit
|
|
TO_BLOCK* block, //block it came from
|
|
int32_t& segments, //no fo segments
|
|
int32_t* xstarts //coords of segments
|
|
) {
|
|
bool needs_curve; //needs curved line
|
|
int blobcount; //no of blobs
|
|
int blobindex; //current blob
|
|
int last_state; //above, on , below
|
|
int state; //of current blob
|
|
float yshift; //from baseline
|
|
TBOX box; //blob box
|
|
TBOX new_box; //new_it box
|
|
float middle; //xcentre of blob
|
|
//blobs
|
|
BLOBNBOX_IT blob_it = row->blob_list ();
|
|
BLOBNBOX_IT new_it = blob_it; //front end
|
|
SORTED_FLOATS yshifts; //shifts from baseline
|
|
|
|
needs_curve = false;
|
|
box = box_next_pre_chopped (&blob_it);
|
|
xstarts[0] = box.left ();
|
|
segments = 1;
|
|
blobcount = row->blob_list ()->length ();
|
|
if (textord_oldbl_debug)
|
|
tprintf ("Segmenting baseline of %d blobs at (%d,%d)\n",
|
|
blobcount, box.left (), box.bottom ());
|
|
if (blobcount <= textord_spline_medianwin
|
|
|| blobcount < textord_spline_minblobs) {
|
|
blob_it.move_to_last ();
|
|
box = blob_it.data ()->bounding_box ();
|
|
xstarts[1] = box.right ();
|
|
return false;
|
|
}
|
|
last_state = 0;
|
|
new_it.mark_cycle_pt ();
|
|
for (blobindex = 0; blobindex < textord_spline_medianwin; blobindex++) {
|
|
new_box = box_next_pre_chopped (&new_it);
|
|
middle = (new_box.left () + new_box.right ()) / 2.0;
|
|
yshift = new_box.bottom () - row->line_m () * middle - row->line_c ();
|
|
//record shift
|
|
yshifts.add (yshift, blobindex);
|
|
if (new_it.cycled_list ()) {
|
|
xstarts[1] = new_box.right ();
|
|
return false;
|
|
}
|
|
}
|
|
for (blobcount = 0; blobcount < textord_spline_medianwin / 2; blobcount++)
|
|
box = box_next_pre_chopped (&blob_it);
|
|
do {
|
|
new_box = box_next_pre_chopped (&new_it);
|
|
//get middle one
|
|
yshift = yshifts[textord_spline_medianwin / 2];
|
|
if (yshift > textord_spline_shift_fraction * block->line_size)
|
|
state = 1;
|
|
else if (-yshift > textord_spline_shift_fraction * block->line_size)
|
|
state = -1;
|
|
else
|
|
state = 0;
|
|
if (state != 0)
|
|
needs_curve = true;
|
|
// tprintf("State=%d, prev=%d, shift=%g\n",
|
|
// state,last_state,yshift);
|
|
if (state != last_state && blobcount > textord_spline_minblobs) {
|
|
xstarts[segments++] = box.left ();
|
|
blobcount = 0;
|
|
}
|
|
last_state = state;
|
|
yshifts.remove (blobindex - textord_spline_medianwin);
|
|
box = box_next_pre_chopped (&blob_it);
|
|
middle = (new_box.left () + new_box.right ()) / 2.0;
|
|
yshift = new_box.bottom () - row->line_m () * middle - row->line_c ();
|
|
yshifts.add (yshift, blobindex);
|
|
blobindex++;
|
|
blobcount++;
|
|
}
|
|
while (!new_it.cycled_list ());
|
|
if (blobcount > textord_spline_minblobs || segments == 1) {
|
|
xstarts[segments] = new_box.right ();
|
|
}
|
|
else {
|
|
xstarts[--segments] = new_box.right ();
|
|
}
|
|
if (textord_oldbl_debug)
|
|
tprintf ("Made %d segments on row at (%d,%d)\n",
|
|
segments, box.right (), box.bottom ());
|
|
return needs_curve;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name linear_spline_baseline
|
|
*
|
|
* Divide the baseline up into segments which require a different
|
|
* quadratic fitted to them.
|
|
* @return TRUE if enough blobs were far enough away to need a quadratic.
|
|
*/
|
|
double *
|
|
linear_spline_baseline ( //split baseline
|
|
TO_ROW * row, //row to fit
|
|
TO_BLOCK * block, //block it came from
|
|
int32_t & segments, //no fo segments
|
|
int32_t xstarts[] //coords of segments
|
|
) {
|
|
int blobcount; //no of blobs
|
|
int blobindex; //current blob
|
|
int index1, index2; //blob numbers
|
|
int blobs_per_segment; //blobs in each
|
|
TBOX box; //blob box
|
|
TBOX new_box; //new_it box
|
|
//blobs
|
|
BLOBNBOX_IT blob_it = row->blob_list ();
|
|
BLOBNBOX_IT new_it = blob_it; //front end
|
|
float b, c; //fitted curve
|
|
tesseract::DetLineFit lms;
|
|
int32_t segment; //current segment
|
|
|
|
box = box_next_pre_chopped (&blob_it);
|
|
xstarts[0] = box.left ();
|
|
blobcount = 1;
|
|
while (!blob_it.at_first ()) {
|
|
blobcount++;
|
|
box = box_next_pre_chopped (&blob_it);
|
|
}
|
|
segments = blobcount / textord_spline_medianwin;
|
|
if (segments < 1)
|
|
segments = 1;
|
|
blobs_per_segment = blobcount / segments;
|
|
// quadratic coeffs
|
|
double *coeffs = new double[segments * 3];
|
|
if (textord_oldbl_debug)
|
|
tprintf
|
|
("Linear splining baseline of %d blobs at (%d,%d), into %d segments of %d blobs\n",
|
|
blobcount, box.left (), box.bottom (), segments, blobs_per_segment);
|
|
segment = 1;
|
|
for (index2 = 0; index2 < blobs_per_segment / 2; index2++)
|
|
box_next_pre_chopped(&new_it);
|
|
index1 = 0;
|
|
blobindex = index2;
|
|
do {
|
|
blobindex += blobs_per_segment;
|
|
lms.Clear();
|
|
while (index1 < blobindex || (segment == segments && index1 < blobcount)) {
|
|
box = box_next_pre_chopped (&blob_it);
|
|
int middle = (box.left() + box.right()) / 2;
|
|
lms.Add(ICOORD(middle, box.bottom()));
|
|
index1++;
|
|
if (index1 == blobindex - blobs_per_segment / 2
|
|
|| index1 == blobcount - 1) {
|
|
xstarts[segment] = box.left ();
|
|
}
|
|
}
|
|
lms.Fit(&b, &c);
|
|
coeffs[segment * 3 - 3] = 0;
|
|
coeffs[segment * 3 - 2] = b;
|
|
coeffs[segment * 3 - 1] = c;
|
|
segment++;
|
|
if (segment > segments)
|
|
break;
|
|
|
|
blobindex += blobs_per_segment;
|
|
lms.Clear();
|
|
while (index2 < blobindex || (segment == segments && index2 < blobcount)) {
|
|
new_box = box_next_pre_chopped (&new_it);
|
|
int middle = (new_box.left() + new_box.right()) / 2;
|
|
lms.Add(ICOORD (middle, new_box.bottom()));
|
|
index2++;
|
|
if (index2 == blobindex - blobs_per_segment / 2
|
|
|| index2 == blobcount - 1) {
|
|
xstarts[segment] = new_box.left ();
|
|
}
|
|
}
|
|
lms.Fit(&b, &c);
|
|
coeffs[segment * 3 - 3] = 0;
|
|
coeffs[segment * 3 - 2] = b;
|
|
coeffs[segment * 3 - 1] = c;
|
|
segment++;
|
|
}
|
|
while (segment <= segments);
|
|
return coeffs;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name assign_blobs_to_rows
|
|
*
|
|
* Make enough rows to allocate all the given blobs to one.
|
|
* If a block skew is given, use that, else attempt to track it.
|
|
*/
|
|
void assign_blobs_to_rows( //find lines
|
|
TO_BLOCK* block, //block to do
|
|
float* gradient, //block skew
|
|
int pass, //identification
|
|
bool reject_misses, //chuck big ones out
|
|
bool make_new_rows, //add rows for unmatched
|
|
bool drawing_skew //draw smoothed skew
|
|
) {
|
|
OVERLAP_STATE overlap_result; //what to do with it
|
|
float ycoord; //current y
|
|
float top, bottom; //of blob
|
|
float g_length = 1.0f; //from gradient
|
|
int16_t row_count; //no of rows
|
|
int16_t left_x; //left edge
|
|
int16_t last_x; //previous edge
|
|
float block_skew; //y delta
|
|
float smooth_factor; //for new coords
|
|
float near_dist; //dist to nearest row
|
|
ICOORD testpt; //testing only
|
|
BLOBNBOX *blob; //current blob
|
|
TO_ROW *row; //current row
|
|
TO_ROW *dest_row = nullptr; //row to put blob in
|
|
//iterators
|
|
BLOBNBOX_IT blob_it = &block->blobs;
|
|
TO_ROW_IT row_it = block->get_rows ();
|
|
|
|
ycoord =
|
|
(block->block->pdblk.bounding_box ().bottom () +
|
|
block->block->pdblk.bounding_box ().top ()) / 2.0f;
|
|
if (gradient != nullptr)
|
|
g_length = sqrt (1 + *gradient * *gradient);
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (drawing_skew)
|
|
to_win->SetCursor(block->block->pdblk.bounding_box ().left (), ycoord);
|
|
#endif
|
|
testpt = ICOORD (textord_test_x, textord_test_y);
|
|
blob_it.sort (blob_x_order);
|
|
smooth_factor = 1.0;
|
|
block_skew = 0.0f;
|
|
row_count = row_it.length (); //might have rows
|
|
if (!blob_it.empty ()) {
|
|
left_x = blob_it.data ()->bounding_box ().left ();
|
|
}
|
|
else {
|
|
left_x = block->block->pdblk.bounding_box ().left ();
|
|
}
|
|
last_x = left_x;
|
|
for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ()) {
|
|
blob = blob_it.data ();
|
|
if (gradient != nullptr) {
|
|
block_skew = (1 - 1 / g_length) * blob->bounding_box ().bottom ()
|
|
+ *gradient / g_length * blob->bounding_box ().left ();
|
|
}
|
|
else if (blob->bounding_box ().left () - last_x > block->line_size / 2
|
|
&& last_x - left_x > block->line_size * 2
|
|
&& textord_interpolating_skew) {
|
|
// tprintf("Interpolating skew from %g",block_skew);
|
|
block_skew *= (float) (blob->bounding_box ().left () - left_x)
|
|
/ (last_x - left_x);
|
|
// tprintf("to %g\n",block_skew);
|
|
}
|
|
last_x = blob->bounding_box ().left ();
|
|
top = blob->bounding_box ().top () - block_skew;
|
|
bottom = blob->bounding_box ().bottom () - block_skew;
|
|
#ifndef GRAPHICS_DISABLED
|
|
if (drawing_skew)
|
|
to_win->DrawTo(blob->bounding_box ().left (), ycoord + block_skew);
|
|
#endif
|
|
if (!row_it.empty ()) {
|
|
for (row_it.move_to_first ();
|
|
!row_it.at_last () && row_it.data ()->min_y () > top;
|
|
row_it.forward ());
|
|
row = row_it.data ();
|
|
if (row->min_y () <= top && row->max_y () >= bottom) {
|
|
//any overlap
|
|
dest_row = row;
|
|
overlap_result = most_overlapping_row (&row_it, dest_row,
|
|
top, bottom,
|
|
block->line_size,
|
|
blob->bounding_box ().
|
|
contains (testpt));
|
|
if (overlap_result == NEW_ROW && !reject_misses)
|
|
overlap_result = ASSIGN;
|
|
}
|
|
else {
|
|
overlap_result = NEW_ROW;
|
|
if (!make_new_rows) {
|
|
near_dist = row_it.data_relative (-1)->min_y () - top;
|
|
//below bottom
|
|
if (bottom < row->min_y ()) {
|
|
if (row->min_y () - bottom <=
|
|
(block->line_spacing -
|
|
block->line_size) * tesseract::CCStruct::kDescenderFraction) {
|
|
//done it
|
|
overlap_result = ASSIGN;
|
|
dest_row = row;
|
|
}
|
|
}
|
|
else if (near_dist > 0
|
|
&& near_dist < bottom - row->max_y ()) {
|
|
row_it.backward ();
|
|
dest_row = row_it.data ();
|
|
if (dest_row->min_y () - bottom <=
|
|
(block->line_spacing -
|
|
block->line_size) * tesseract::CCStruct::kDescenderFraction) {
|
|
//done it
|
|
overlap_result = ASSIGN;
|
|
}
|
|
}
|
|
else {
|
|
if (top - row->max_y () <=
|
|
(block->line_spacing -
|
|
block->line_size) * (textord_overlap_x +
|
|
tesseract::CCStruct::kAscenderFraction)) {
|
|
//done it
|
|
overlap_result = ASSIGN;
|
|
dest_row = row;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (overlap_result == ASSIGN)
|
|
dest_row->add_blob (blob_it.extract (), top, bottom,
|
|
block->line_size);
|
|
if (overlap_result == NEW_ROW) {
|
|
if (make_new_rows && top - bottom < block->max_blob_size) {
|
|
dest_row =
|
|
new TO_ROW (blob_it.extract (), top, bottom,
|
|
block->line_size);
|
|
row_count++;
|
|
if (bottom > row_it.data ()->min_y ())
|
|
row_it.add_before_then_move (dest_row);
|
|
//insert in right place
|
|
else
|
|
row_it.add_after_then_move (dest_row);
|
|
smooth_factor =
|
|
1.0 / (row_count * textord_skew_lag +
|
|
textord_skewsmooth_offset);
|
|
}
|
|
else
|
|
overlap_result = REJECT;
|
|
}
|
|
}
|
|
else if (make_new_rows && top - bottom < block->max_blob_size) {
|
|
overlap_result = NEW_ROW;
|
|
dest_row =
|
|
new TO_ROW(blob_it.extract(), top, bottom, block->line_size);
|
|
row_count++;
|
|
row_it.add_after_then_move(dest_row);
|
|
smooth_factor = 1.0 / (row_count * textord_skew_lag +
|
|
textord_skewsmooth_offset2);
|
|
}
|
|
else
|
|
overlap_result = REJECT;
|
|
if (blob->bounding_box ().contains(testpt) && textord_debug_blob) {
|
|
if (overlap_result != REJECT) {
|
|
tprintf("Test blob assigned to row at (%g,%g) on pass %d\n",
|
|
dest_row->min_y(), dest_row->max_y(), pass);
|
|
}
|
|
else {
|
|
tprintf("Test blob assigned to no row on pass %d\n", pass);
|
|
}
|
|
}
|
|
if (overlap_result != REJECT) {
|
|
while (!row_it.at_first() &&
|
|
row_it.data()->min_y() > row_it.data_relative(-1)->min_y()) {
|
|
row = row_it.extract();
|
|
row_it.backward();
|
|
row_it.add_before_then_move(row);
|
|
}
|
|
while (!row_it.at_last() &&
|
|
row_it.data ()->min_y() < row_it.data_relative (1)->min_y()) {
|
|
row = row_it.extract();
|
|
row_it.forward();
|
|
// Keep rows in order.
|
|
row_it.add_after_then_move(row);
|
|
}
|
|
BLOBNBOX_IT added_blob_it(dest_row->blob_list());
|
|
added_blob_it.move_to_last();
|
|
TBOX prev_box = added_blob_it.data_relative(-1)->bounding_box();
|
|
if (dest_row->blob_list()->singleton() ||
|
|
!prev_box.major_x_overlap(blob->bounding_box())) {
|
|
block_skew = (1 - smooth_factor) * block_skew
|
|
+ smooth_factor * (blob->bounding_box().bottom() -
|
|
dest_row->initial_min_y());
|
|
}
|
|
}
|
|
}
|
|
for (row_it.mark_cycle_pt(); !row_it.cycled_list(); row_it.forward()) {
|
|
if (row_it.data()->blob_list()->empty())
|
|
delete row_it.extract(); // Discard empty rows.
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* @name most_overlapping_row
|
|
*
|
|
* Return the row which most overlaps the blob.
|
|
*/
|
|
OVERLAP_STATE most_overlapping_row( //find best row
|
|
TO_ROW_IT* row_it, //iterator
|
|
TO_ROW*& best_row, //output row
|
|
float top, //top of blob
|
|
float bottom, //bottom of blob
|
|
float rowsize, //max row size
|
|
bool testing_blob //test stuff
|
|
) {
|
|
OVERLAP_STATE result; //result of tests
|
|
float overlap; //of blob & row
|
|
float bestover; //nearest row
|
|
float merge_top, merge_bottom; //size of merged row
|
|
ICOORD testpt; //testing only
|
|
TO_ROW *row; //current row
|
|
TO_ROW *test_row; //for multiple overlaps
|
|
BLOBNBOX_IT blob_it; //for merging rows
|
|
|
|
result = ASSIGN;
|
|
row = row_it->data ();
|
|
bestover = top - bottom;
|
|
if (top > row->max_y ())
|
|
bestover -= top - row->max_y ();
|
|
if (bottom < row->min_y ())
|
|
//compute overlap
|
|
bestover -= row->min_y () - bottom;
|
|
if (testing_blob && textord_debug_blob) {
|
|
tprintf("Test blob y=(%g,%g), row=(%f,%f), size=%g, overlap=%f\n",
|
|
bottom, top, row->min_y(), row->max_y(), rowsize, bestover);
|
|
}
|
|
test_row = row;
|
|
do {
|
|
if (!row_it->at_last ()) {
|
|
row_it->forward ();
|
|
test_row = row_it->data ();
|
|
if (test_row->min_y () <= top && test_row->max_y () >= bottom) {
|
|
merge_top =
|
|
test_row->max_y () >
|
|
row->max_y ()? test_row->max_y () : row->max_y ();
|
|
merge_bottom =
|
|
test_row->min_y () <
|
|
row->min_y ()? test_row->min_y () : row->min_y ();
|
|
if (merge_top - merge_bottom <= rowsize) {
|
|
if (testing_blob) {
|
|
tprintf ("Merging rows at (%g,%g), (%g,%g)\n",
|
|
row->min_y (), row->max_y (),
|
|
test_row->min_y (), test_row->max_y ());
|
|
}
|
|
test_row->set_limits (merge_bottom, merge_top);
|
|
blob_it.set_to_list (test_row->blob_list ());
|
|
blob_it.add_list_after (row->blob_list ());
|
|
blob_it.sort (blob_x_order);
|
|
row_it->backward ();
|
|
delete row_it->extract ();
|
|
row_it->forward ();
|
|
bestover = -1.0f; //force replacement
|
|
}
|
|
overlap = top - bottom;
|
|
if (top > test_row->max_y ())
|
|
overlap -= top - test_row->max_y ();
|
|
if (bottom < test_row->min_y ())
|
|
overlap -= test_row->min_y () - bottom;
|
|
if (bestover >= rowsize - 1 && overlap >= rowsize - 1) {
|
|
result = REJECT;
|
|
}
|
|
if (overlap > bestover) {
|
|
bestover = overlap; //find biggest overlap
|
|
row = test_row;
|
|
}
|
|
if (testing_blob && textord_debug_blob) {
|
|
tprintf("Test blob y=(%g,%g), row=(%f,%f), size=%g, overlap=%f->%f\n",
|
|
bottom, top, test_row->min_y(), test_row->max_y(),
|
|
rowsize, overlap, bestover);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
while (!row_it->at_last ()
|
|
&& test_row->min_y () <= top && test_row->max_y () >= bottom);
|
|
while (row_it->data () != row)
|
|
row_it->backward (); //make it point to row
|
|
//doesn't overlap much
|
|
if (top - bottom - bestover > rowsize * textord_overlap_x &&
|
|
(!textord_fix_makerow_bug || bestover < rowsize * textord_overlap_x)
|
|
&& result == ASSIGN)
|
|
result = NEW_ROW; //doesn't overlap enough
|
|
best_row = row;
|
|
return result;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name blob_x_order
|
|
*
|
|
* Sort function to sort blobs in x from page left.
|
|
*/
|
|
int blob_x_order( //sort function
|
|
const void *item1, //items to compare
|
|
const void *item2) {
|
|
//converted ptr
|
|
BLOBNBOX *blob1 = *(BLOBNBOX **) item1;
|
|
//converted ptr
|
|
BLOBNBOX *blob2 = *(BLOBNBOX **) item2;
|
|
|
|
if (blob1->bounding_box ().left () < blob2->bounding_box ().left ())
|
|
return -1;
|
|
else if (blob1->bounding_box ().left () > blob2->bounding_box ().left ())
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name row_y_order
|
|
*
|
|
* Sort function to sort rows in y from page top.
|
|
*/
|
|
int row_y_order( //sort function
|
|
const void *item1, //items to compare
|
|
const void *item2) {
|
|
//converted ptr
|
|
TO_ROW *row1 = *(TO_ROW **) item1;
|
|
//converted ptr
|
|
TO_ROW *row2 = *(TO_ROW **) item2;
|
|
|
|
if (row1->parallel_c () > row2->parallel_c ())
|
|
return -1;
|
|
else if (row1->parallel_c () < row2->parallel_c ())
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* @name row_spacing_order
|
|
*
|
|
* Qsort style function to compare 2 TO_ROWS based on their spacing value.
|
|
*/
|
|
int row_spacing_order( //sort function
|
|
const void *item1, //items to compare
|
|
const void *item2) {
|
|
//converted ptr
|
|
TO_ROW *row1 = *(TO_ROW **) item1;
|
|
//converted ptr
|
|
TO_ROW *row2 = *(TO_ROW **) item2;
|
|
|
|
if (row1->spacing < row2->spacing)
|
|
return -1;
|
|
else if (row1->spacing > row2->spacing)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* @name mark_repeated_chars
|
|
*
|
|
* Mark blobs marked with BTFT_LEADER in repeated sets using the
|
|
* repeated_set member of BLOBNBOX.
|
|
*/
|
|
void mark_repeated_chars(TO_ROW *row) {
|
|
BLOBNBOX_IT box_it(row->blob_list()); // Iterator.
|
|
int num_repeated_sets = 0;
|
|
if (!box_it.empty()) {
|
|
do {
|
|
BLOBNBOX* bblob = box_it.data();
|
|
int repeat_length = 1;
|
|
if (bblob->flow() == BTFT_LEADER &&
|
|
!bblob->joined_to_prev() && bblob->cblob() != nullptr) {
|
|
BLOBNBOX_IT test_it(box_it);
|
|
for (test_it.forward(); !test_it.at_first();) {
|
|
bblob = test_it.data();
|
|
if (bblob->flow() != BTFT_LEADER)
|
|
break;
|
|
test_it.forward();
|
|
bblob = test_it.data();
|
|
if (bblob->joined_to_prev() || bblob->cblob() == nullptr) {
|
|
repeat_length = 0;
|
|
break;
|
|
}
|
|
++repeat_length;
|
|
}
|
|
}
|
|
if (repeat_length >= kMinLeaderCount) {
|
|
num_repeated_sets++;
|
|
for (; repeat_length > 0; box_it.forward(), --repeat_length) {
|
|
bblob = box_it.data();
|
|
bblob->set_repeated_set(num_repeated_sets);
|
|
}
|
|
} else {
|
|
bblob->set_repeated_set(0);
|
|
box_it.forward();
|
|
}
|
|
} while (!box_it.at_first()); // until all done
|
|
}
|
|
row->set_num_repeated_sets(num_repeated_sets);
|
|
}
|