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425d593ebe
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk/trunk@2 d0cd1f9f-072b-0410-8dd7-cf729c803f20
408 lines
15 KiB
C++
408 lines
15 KiB
C++
/**********************************************************************
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* File: edgblob.c (Formerly edgeloop.c)
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* Description: Functions to clean up an outline before approximation.
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* Author: Ray Smith
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* Created: Tue Mar 26 16:56:25 GMT 1991
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*
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* (C) Copyright 1991, 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 "mfcpch.h"
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//#include "dirtab.h"
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#include "scanedg.h"
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#include "drawedg.h"
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#include "edgloop.h"
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#include "edgblob.h"
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#define EXTERN
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EXTERN INT_VAR (edges_children_per_grandchild, 10,
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"Importance ratio for chucking outlines");
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EXTERN INT_VAR (edges_children_count_limit, 45, "Max holes allowed in blob");
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EXTERN BOOL_VAR (edges_children_fix, FALSE,
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"Remove boxy parents of char-like children");
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EXTERN INT_VAR (edges_min_nonhole, 12,
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"Min pixels for potential char in box");
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EXTERN INT_VAR (edges_patharea_ratio, 40,
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"Max lensq/area for acceptable child outline");
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EXTERN double_VAR (edges_childarea, 0.5,
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"Max area fraction of child outline");
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EXTERN double_VAR (edges_boxarea, 0.8,
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"Min area fraction of grandchild for box");
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/**********************************************************************
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* OL_BUCKETS::OL_BUCKETS
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*
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* Construct an array of buckets for associating outlines into blobs.
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**********************************************************************/
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OL_BUCKETS::OL_BUCKETS (
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////constructor
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ICOORD bleft, //corners
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ICOORD tright): bl (bleft), tr (tright) {
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bxdim = (tright.x () - bleft.x ()) / BUCKETSIZE + 1;
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bydim = (tright.y () - bleft.y ()) / BUCKETSIZE + 1;
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//make array
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buckets = new C_OUTLINE_LIST[bxdim * bydim];
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index = 0;
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}
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/**********************************************************************
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* OL_BUCKETS::operator(
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*
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* Return a pointer to a list of C_OUTLINEs corresponding to the
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* given pixel coordinates.
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**********************************************************************/
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C_OUTLINE_LIST *
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OL_BUCKETS::operator () ( //array access
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INT16 x, //image coords
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INT16 y) {
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return &buckets[(y - bl.y ()) / BUCKETSIZE * bxdim +
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(x - bl.x ()) / BUCKETSIZE];
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}
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/**********************************************************************
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* OL_BUCKETS::count_children
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*
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* Find number of descendants of this outline.
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**********************************************************************/
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INT32 OL_BUCKETS::count_children( //recursive count
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C_OUTLINE *outline, //parent outline
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INT32 max_count //max output
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) {
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BOOL8 parent_box; //could it be boxy
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INT16 xmin, xmax; //coord limits
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INT16 ymin, ymax;
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INT16 xindex, yindex; //current bucket
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C_OUTLINE *child; //current child
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INT32 child_count; //no of children
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INT32 grandchild_count; //no of grandchildren
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INT32 parent_area; //potential box
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FLOAT32 max_parent_area; //potential box
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INT32 child_area; //current child
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INT32 child_length; //current child
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BOX olbox;
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C_OUTLINE_IT child_it; //search iterator
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olbox = outline->bounding_box ();
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xmin = (olbox.left () - bl.x ()) / BUCKETSIZE;
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xmax = (olbox.right () - bl.x ()) / BUCKETSIZE;
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ymin = (olbox.bottom () - bl.y ()) / BUCKETSIZE;
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ymax = (olbox.top () - bl.y ()) / BUCKETSIZE;
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child_count = 0;
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grandchild_count = 0;
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parent_area = 0;
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max_parent_area = 0;
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parent_box = TRUE;
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for (yindex = ymin; yindex <= ymax; yindex++) {
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for (xindex = xmin; xindex <= xmax; xindex++) {
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child_it.set_to_list (&buckets[yindex * bxdim + xindex]);
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if (child_it.empty ())
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continue;
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for (child_it.mark_cycle_pt (); !child_it.cycled_list ();
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child_it.forward ()) {
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child = child_it.data ();
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if (child != outline && *child < *outline) {
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child_count++;
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if (child_count <= max_count)
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grandchild_count += count_children (child,
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(max_count -
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child_count) /
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edges_children_per_grandchild)
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* edges_children_per_grandchild;
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if (child_count + grandchild_count > max_count) {
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/* err.log(RESULT_OKAY,E_LOC,ERR_OCR,
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ERR_SCROLLING,ERR_CONTINUE,ERR_DEBUG,
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"Discarding parent with child count=%d, gc=%d",
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child_count,grandchild_count);*/
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return child_count + grandchild_count;
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}
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if (parent_area == 0) {
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parent_area = outline->outer_area ();
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if (parent_area < 0)
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parent_area = -parent_area;
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max_parent_area = outline->bounding_box ().width ()
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* outline->bounding_box ().height () * edges_boxarea;
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if (parent_area < max_parent_area)
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parent_box = FALSE;
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}
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if (parent_box
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&& (!edges_children_fix
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|| child->bounding_box ().height () >
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edges_min_nonhole) /**/) {
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child_area = child->outer_area ();
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if (child_area < 0)
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child_area = -child_area;
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if (edges_children_fix) {
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if (parent_area - child_area < max_parent_area) {
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parent_box = FALSE;
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continue;
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}
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if (grandchild_count > 0) {
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/* err.log(RESULT_OKAY,E_LOC,ERR_OCR,
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ERR_SCROLLING,ERR_CONTINUE,ERR_DEBUG,
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"Discarding parent of area %d, child area=%d, max%g with gc=%d",
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parent_area,child_area,max_parent_area,grandchild_count);*/
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return max_count + 1;
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}
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child_length = child->pathlength ();
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if (child_length * child_length >
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child_area * edges_patharea_ratio) {
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/*/ err.log(RESULT_OKAY,E_LOC,ERR_OCR,
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ERR_SCROLLING,ERR_CONTINUE,ERR_DEBUG,
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"Discarding parent of area %d, child area=%d, max%g with child length=%d",
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parent_area,child_area,max_parent_area,child_length);*/
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return max_count + 1;
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}
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}
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if (child_area < child->bounding_box ().width ()
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* child->bounding_box ().height () *
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edges_childarea) {
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/* err.log(RESULT_OKAY,E_LOC,ERR_OCR,
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ERR_SCROLLING,ERR_CONTINUE,ERR_DEBUG,
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"Discarding parent of area %d, child area=%d, max%g with child rect=%d",
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parent_area,child_area,max_parent_area,child->bounding_box().width()
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*child->bounding_box().height()); */
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return max_count + 1;
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}
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}
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}
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}
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}
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}
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return child_count + grandchild_count;
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}
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/**********************************************************************
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* OL_BUCKETS::extract_children
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*
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* Find number of descendants of this outline.
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**********************************************************************/
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void OL_BUCKETS::extract_children( //recursive count
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C_OUTLINE *outline, //parent outline
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C_OUTLINE_IT *it //destination iterator
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) {
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INT16 xmin, xmax; //coord limits
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INT16 ymin, ymax;
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INT16 xindex, yindex; //current bucket
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BOX olbox;
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C_OUTLINE_IT child_it; //search iterator
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olbox = outline->bounding_box ();
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xmin = (olbox.left () - bl.x ()) / BUCKETSIZE;
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xmax = (olbox.right () - bl.x ()) / BUCKETSIZE;
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ymin = (olbox.bottom () - bl.y ()) / BUCKETSIZE;
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ymax = (olbox.top () - bl.y ()) / BUCKETSIZE;
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for (yindex = ymin; yindex <= ymax; yindex++) {
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for (xindex = xmin; xindex <= xmax; xindex++) {
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child_it.set_to_list (&buckets[yindex * bxdim + xindex]);
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for (child_it.mark_cycle_pt (); !child_it.cycled_list ();
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child_it.forward ()) {
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if (*child_it.data () < *outline) {
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it->add_after_then_move (child_it.extract ());
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}
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}
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}
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}
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}
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/**********************************************************************
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* extract_edges
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*
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* Run the edge detector over the block and return a list of blobs.
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**********************************************************************/
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void extract_edges( //find blobs
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#ifndef GRAPHICS_DISABLED
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WINDOW window, //window for output
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#endif
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IMAGE *image, //image to scan
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IMAGE *t_image, //thresholded image
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ICOORD page_tr, //corner of page
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BLOCK *block //block to scan
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) {
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ICOORD bleft; //block box
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ICOORD tright;
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C_OUTLINE_LIST outlines; //outlines in block
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//iterator
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C_OUTLINE_IT out_it = &outlines;
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#ifndef GRAPHICS_DISABLED
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get_outlines (window, image, t_image, page_tr, (PDBLK *) block, &out_it);
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#else
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get_outlines (image, t_image, page_tr, (PDBLK *) block, &out_it);
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#endif
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//block box
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block->bounding_box (bleft, tright);
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//make blobs
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outlines_to_blobs(block, bleft, tright, &outlines);
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}
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/**********************************************************************
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* outlines_to_blobs
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*
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* Gather together outlines into blobs using the usual bucket sort.
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**********************************************************************/
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void outlines_to_blobs( //find blobs
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BLOCK *block, //block to scan
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ICOORD bleft, //block box //outlines in block
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ICOORD tright,
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C_OUTLINE_LIST *outlines) {
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//make buckets
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OL_BUCKETS buckets(bleft, tright);
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fill_buckets(outlines, &buckets);
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empty_buckets(block, &buckets);
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}
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/**********************************************************************
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* fill_buckets
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*
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* Run the edge detector over the block and return a list of blobs.
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**********************************************************************/
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void fill_buckets( //find blobs
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C_OUTLINE_LIST *outlines, //outlines in block
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OL_BUCKETS *buckets //output buckets
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) {
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BOX ol_box; //outline box
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C_OUTLINE_IT out_it = outlines;//iterator
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C_OUTLINE_IT bucket_it; //iterator in bucket
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C_OUTLINE *outline; //current outline
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for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
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outline = out_it.extract (); //take off list
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//get box
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ol_box = outline->bounding_box ();
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bucket_it.set_to_list ((*buckets) (ol_box.left (), ol_box.bottom ()));
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bucket_it.add_to_end (outline);
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}
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}
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/**********************************************************************
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* empty_buckets
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*
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* Run the edge detector over the block and return a list of blobs.
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**********************************************************************/
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void empty_buckets( //find blobs
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BLOCK *block, //block to scan
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OL_BUCKETS *buckets //output buckets
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) {
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BOOL8 good_blob; //healthy blob
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C_OUTLINE_LIST outlines; //outlines in block
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//iterator
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C_OUTLINE_IT out_it = &outlines;
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C_OUTLINE_IT bucket_it = buckets->start_scan ();
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C_OUTLINE_IT parent_it; //parent outline
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C_BLOB *blob; //new blob
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C_BLOB_IT good_blobs = block->blob_list ();
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C_BLOB_IT junk_blobs = block->reject_blobs ();
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while (!bucket_it.empty ()) {
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out_it.set_to_list (&outlines);
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do {
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parent_it = bucket_it; //find outermost
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do
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bucket_it.forward ();
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while (!bucket_it.at_first ()
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&& !(*parent_it.data () < *bucket_it.data ()));
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}
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while (!bucket_it.at_first ());
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//move to new list
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out_it.add_after_then_move (parent_it.extract ());
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good_blob = capture_children (buckets, &junk_blobs, &out_it);
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blob = new C_BLOB (&outlines);
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if (good_blob)
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good_blobs.add_after_then_move (blob);
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else
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junk_blobs.add_after_then_move (blob);
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bucket_it.set_to_list (buckets->scan_next ());
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}
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}
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/**********************************************************************
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* capture_children
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*
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* Find all neighbouring outlines that are children of this outline
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* and either move them to the output list or declare this outline
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* illegal and return FALSE.
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**********************************************************************/
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BOOL8 capture_children( //find children
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OL_BUCKETS *buckets, //bucket sort clanss
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C_BLOB_IT *reject_it, //dead grandchildren
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C_OUTLINE_IT *blob_it //output outlines
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) {
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BOOL8 anydone; //anything canned
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C_OUTLINE *outline; //master outline
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C_OUTLINE *child; //child under test
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C_OUTLINE_IT test_it; //for grandchildren
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INT32 child_count; //no of children
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C_BLOB *blob; //reject
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C_OUTLINE_LIST r_list; //rejects
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C_OUTLINE_IT r_it; //iterator
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outline = blob_it->data ();
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child_count = buckets->count_children (outline, edges_children_count_limit);
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if (child_count > edges_children_count_limit)
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return FALSE;
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if (child_count == 0)
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return TRUE;
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//get single level
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buckets->extract_children (outline, blob_it);
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if (child_count == 1)
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return TRUE;
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do {
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anydone = FALSE;
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blob_it->move_to_first ();
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for (blob_it->mark_cycle_pt (); !blob_it->cycled_list ();
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blob_it->forward ()) {
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child = blob_it->data ();
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if (child != outline) {
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for (test_it = *blob_it, test_it.mark_cycle_pt ();
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!test_it.cycled_list (); test_it.forward ()) {
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if (test_it.data () != child && *test_it.data () < *child) {
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r_it.set_to_list (&r_list);
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r_it.add_after_then_move (test_it.extract ());
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//turn to blob
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blob = new C_BLOB (&r_list);
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reject_it->add_after_then_move (blob);
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anydone = TRUE;
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}
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}
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if (anydone)
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break; //got to reatart
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}
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}
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}
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while (anydone); //got to restart
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return TRUE;
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}
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