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https://github.com/tesseract-ocr/tesseract.git
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10c1169d98
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@860 d0cd1f9f-072b-0410-8dd7-cf729c803f20
171 lines
6.1 KiB
C++
171 lines
6.1 KiB
C++
/*****************************************************************************
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*
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* File: blkocc.cpp (Formerly blockocc.c)
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* Description: Block Occupancy routines
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* Author: Chris Newton
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* Created: Fri Nov 8
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* Modified:
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* Language: C++
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* Package: N/A
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* Status: Experimental (Do Not Distribute)
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*
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* (c) Copyright 1991, Hewlett-Packard Company.
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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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/*
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----------------------------------------------------------------------
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I n c l u d e s
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----------------------------------------------------------------------
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*/
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#include <ctype.h>
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#include <math.h>
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#include "errcode.h"
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#include "drawtord.h"
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#include "blkocc.h"
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#include "helpers.h"
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double_VAR(textord_underline_threshold, 0.5, "Fraction of width occupied");
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// Forward declarations of static functions
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static void horizontal_cblob_projection(C_BLOB *blob, // blob to project
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STATS *stats); // output
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static void horizontal_coutline_projection(C_OUTLINE *outline,
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STATS *stats); // output
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/**
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* test_underline
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*
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* Check to see if the blob is an underline.
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* Return TRUE if it is.
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*/
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BOOL8 test_underline( //look for underlines
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BOOL8 testing_on, //< drawing blob
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C_BLOB *blob, //< blob to test
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inT16 baseline, //< coords of baseline
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inT16 xheight //< height of line
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) {
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inT16 occ;
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inT16 blob_width; //width of blob
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TBOX blob_box; //bounding box
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inT32 desc_occ;
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inT32 x_occ;
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inT32 asc_occ;
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STATS projection;
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blob_box = blob->bounding_box ();
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blob_width = blob->bounding_box ().width ();
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projection.set_range (blob_box.bottom (), blob_box.top () + 1);
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if (testing_on) {
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// blob->plot(to_win,GOLDENROD,GOLDENROD);
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// line_color_index(to_win,GOLDENROD);
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// move2d(to_win,blob_box.left(),baseline);
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// draw2d(to_win,blob_box.right(),baseline);
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// move2d(to_win,blob_box.left(),baseline+xheight);
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// draw2d(to_win,blob_box.right(),baseline+xheight);
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tprintf
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("Testing underline on blob at (%d,%d)->(%d,%d), base=%d\nOccs:",
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blob->bounding_box ().left (), blob->bounding_box ().bottom (),
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blob->bounding_box ().right (), blob->bounding_box ().top (),
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baseline);
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}
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horizontal_cblob_projection(blob, &projection);
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desc_occ = 0;
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for (occ = blob_box.bottom (); occ < baseline; occ++)
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if (occ <= blob_box.top () && projection.pile_count (occ) > desc_occ)
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//max in region
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desc_occ = projection.pile_count (occ);
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x_occ = 0;
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for (occ = baseline; occ <= baseline + xheight; occ++)
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if (occ >= blob_box.bottom () && occ <= blob_box.top ()
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&& projection.pile_count (occ) > x_occ)
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//max in region
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x_occ = projection.pile_count (occ);
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asc_occ = 0;
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for (occ = baseline + xheight + 1; occ <= blob_box.top (); occ++)
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if (occ >= blob_box.bottom () && projection.pile_count (occ) > asc_occ)
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asc_occ = projection.pile_count (occ);
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if (testing_on) {
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tprintf ("%d %d %d\n", desc_occ, x_occ, asc_occ);
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}
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if (desc_occ == 0 && x_occ == 0 && asc_occ == 0) {
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tprintf ("Bottom=%d, top=%d, base=%d, x=%d\n",
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blob_box.bottom (), blob_box.top (), baseline, xheight);
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projection.print();
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}
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if (desc_occ > x_occ + x_occ
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&& desc_occ > blob_width * textord_underline_threshold)
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return TRUE; //real underline
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if (asc_occ > x_occ + x_occ
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&& asc_occ > blob_width * textord_underline_threshold)
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return TRUE; //overline
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return FALSE; //neither
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}
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/**
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* horizontal_cblob_projection
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*
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* Compute the horizontal projection of a cblob from its outlines
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* and add to the given STATS.
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*/
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static void horizontal_cblob_projection( //project outlines
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C_BLOB *blob, //< blob to project
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STATS *stats //< output
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) {
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//outlines of blob
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C_OUTLINE_IT out_it = blob->out_list ();
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for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
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horizontal_coutline_projection (out_it.data (), stats);
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}
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}
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/**
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* horizontal_coutline_projection
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*
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* Compute the horizontal projection of a outline from its outlines
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* and add to the given STATS.
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*/
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static void horizontal_coutline_projection( //project outlines
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C_OUTLINE *outline, //< outline to project
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STATS *stats //< output
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) {
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ICOORD pos; //current point
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ICOORD step; //edge step
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inT32 length; //of outline
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inT16 stepindex; //current step
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C_OUTLINE_IT out_it = outline->child ();
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pos = outline->start_pos ();
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length = outline->pathlength ();
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for (stepindex = 0; stepindex < length; stepindex++) {
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step = outline->step (stepindex);
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if (step.y () > 0) {
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stats->add (pos.y (), pos.x ());
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}
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else if (step.y () < 0) {
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stats->add (pos.y () - 1, -pos.x ());
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}
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pos += step;
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}
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for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
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horizontal_coutline_projection (out_it.data (), stats);
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}
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}
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