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425d593ebe
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk/trunk@2 d0cd1f9f-072b-0410-8dd7-cf729c803f20
555 lines
18 KiB
C++
555 lines
18 KiB
C++
/* -*-C-*-
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********************************************************************************
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*
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* File: findseam.c (Formerly findseam.c)
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* Description:
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* Author: Mark Seaman, OCR Technology
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* Created: Fri Oct 16 14:37:00 1987
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* Modified: Tue Jul 30 15:44:59 1991 (Mark Seaman) marks@hpgrlt
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* Language: C
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* Package: N/A
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* Status: Reusable Software Component
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*
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* (c) Copyright 1987, 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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I n c l u d e s
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----------------------------------------------------------------------*/
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#include "findseam.h"
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#include "gradechop.h"
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#include "olutil.h"
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#include "plotedges.h"
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#include "outlines.h"
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#include "freelist.h"
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#include "seam.h"
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/*----------------------------------------------------------------------
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T y p e s
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----------------------------------------------------------------------*/
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#define SPLIT_CLOSENESS 20/* Difference in x value */
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/* How many to keep */
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#define MAX_NUM_SEAMS 150
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/* How many to keep */
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#define MAX_OLD_SEAMS 150
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#define NO_FULL_PRIORITY -1/* Special marker for pri. */
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/* Evalute right away */
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#define GOOD_PARTIAL_PRIORITY good_split
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#define BAD_PRIORITY 9999.0
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/*----------------------------------------------------------------------
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M a c r o s
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----------------------------------------------------------------------*/
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/**********************************************************************
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* add_seam_to_queue
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*
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* Add this seam value to the seam queue. If the heap is already full
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* then nothing is done.
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**********************************************************************/
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#define add_seam_to_queue(seams,seam,priority) \
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if (seam)\
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{\
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if (HeapFull(seams))\
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junk_worst_seam(seams,seam,priority);\
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else\
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HeapPush (seams, priority, (char*) seam);\
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}
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/**********************************************************************
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* best_seam_priority
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*
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* Return the best priority value on the queue.
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**********************************************************************/
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#define best_seam_priority(seam_queue) \
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(HeapEmpty (seam_queue) ? \
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NO_FULL_PRIORITY : \
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((SEAM*) seam_queue_element(seam_queue, 0))->priority)
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/**********************************************************************
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* create_seam_queue
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*
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* Create a new seam queue with no elements in it.
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**********************************************************************/
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#define create_seam_queue(seam_queue) \
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(seam_queue = MakeHeap (MAX_NUM_SEAMS))
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/**********************************************************************
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* create_seam_pile
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*
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* Create a new seam pile with no elements in it.
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**********************************************************************/
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#define create_seam_pile(seam_pile) \
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(seam_pile = array_new (MAX_OLD_SEAMS))
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/**********************************************************************
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* delete_seam_queue
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*
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* Delete a seam queue along with all the seam structures associated
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* with it.
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**********************************************************************/
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#define delete_seam_queue(seam_queue) \
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(FreeHeapData (seam_queue, delete_seam), \
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seam_queue = NULL) \
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/**********************************************************************
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* pop_next_seam
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*
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* Remove the next seam from the queue. Put the seam and priority
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* values in the requested variables. If there was nothing to pop
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* then return FALSE, else return TRUE.
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**********************************************************************/
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#define pop_next_seam(seams,seam,priority) \
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(HeapPop (seams,&priority,&seam) == OK) \
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/**********************************************************************
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* seam_queue_element
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*
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* Return the element from the seam queue at the requested index.
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**********************************************************************/
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#define seam_queue_element(seam_queue,index) \
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((index < SizeOfHeap (seam_queue)) ? \
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HeapDataFor (seam_queue, index) : \
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NULL) \
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/*----------------------------------------------------------------------
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F u n c t i o n s
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----------------------------------------------------------------------*/
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/**********************************************************************
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* junk_worst_seam
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*
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* Delete the worst seam from the queue because it is full.
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**********************************************************************/
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void junk_worst_seam(SEAM_QUEUE seams, SEAM *new_seam, float new_priority) {
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SEAM *seam;
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float priority;
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HeapPopWorst(seams, &priority, &seam);
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if (priority > new_priority) {
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delete_seam(seam); /*get rid of it */
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HeapPush (seams, new_priority, (char *) new_seam);
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}
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else {
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delete_seam(new_seam);
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HeapPush (seams, priority, (char *) seam);
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}
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}
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/**********************************************************************
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* choose_best_seam
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*
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* Choose the best seam that can be created by assembling this a
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* collection of splits. A queue of all the possible seams is
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* maintained. Each new split received is placed in that queue with
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* its partial priority value. These values in the seam queue are
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* evaluated and combined until a good enough seam is found. If no
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* further good seams are being found then this function returns to the
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* caller, who will send more splits. If this function is called with
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* a split of NULL, then no further splits can be supplied by the
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* caller.
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**********************************************************************/
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void choose_best_seam(SEAM_QUEUE seam_queue,
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SEAM_PILE *seam_pile,
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SPLIT *split,
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PRIORITY priority,
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SEAM **seam_result,
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TBLOB *blob) {
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SEAM *seam;
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TPOINT topleft;
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TPOINT botright;
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char str[80];
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float my_priority;
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/* Add seam of split */
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my_priority = priority;
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if (split != NULL) {
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seam = new_seam (my_priority,
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(split->point1->pos.x + split->point1->pos.x) / 2,
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split, NULL, NULL);
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if (chop_debug > 1)
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print_seam ("Partial priority ", seam);
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add_seam_to_queue (seam_queue, seam, (float) my_priority);
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if (my_priority > GOOD_PARTIAL_PRIORITY)
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return;
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}
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blob_bounding_box(blob, &topleft, &botright);
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/* Queue loop */
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while (pop_next_seam (seam_queue, seam, my_priority)) {
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/* Set full priority */
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my_priority = seam_priority (seam, topleft.x, botright.x);
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if (chop_debug) {
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sprintf (str, "Full my_priority %0.0f, ", my_priority);
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print_seam(str, seam);
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}
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if ((*seam_result == NULL || /* Replace answer */
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(*seam_result)->priority > my_priority) && my_priority < ok_split) {
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/* No crossing */
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if (constrained_split (seam->split1, blob)) {
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delete_seam(*seam_result);
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clone_seam(*seam_result, seam);
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(*seam_result)->priority = my_priority;
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}
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else {
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delete_seam(seam);
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seam = NULL;
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my_priority = BAD_PRIORITY;
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}
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}
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if (my_priority < good_split) {
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if (seam)
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delete_seam(seam);
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return; /* Made good answer */
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}
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if (seam) {
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/* Combine with others */
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if (array_count (*seam_pile) < MAX_NUM_SEAMS
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/*|| tessedit_truncate_chopper==0 */ ) {
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combine_seam(seam_queue, *seam_pile, seam);
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*seam_pile = array_push (*seam_pile, seam);
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}
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else
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delete_seam(seam);
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}
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my_priority = best_seam_priority (seam_queue);
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if ((my_priority > ok_split) ||
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(my_priority > GOOD_PARTIAL_PRIORITY && split))
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return;
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}
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}
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/**********************************************************************
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* combine_seam
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*
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* Find other seams to combine with this one. The new seams that result
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* from this union should be added to the seam queue. The return value
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* tells whether or not any additional seams were added to the queue.
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**********************************************************************/
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void combine_seam(SEAM_QUEUE seam_queue, SEAM_PILE seam_pile, SEAM *seam) {
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register INT16 x;
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register INT16 dist;
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INT16 bottom1, top1;
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INT16 bottom2, top2;
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SEAM *new_one;
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SEAM *this_one;
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bottom1 = seam->split1->point1->pos.y;
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if (seam->split1->point2->pos.y >= bottom1)
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top1 = seam->split1->point2->pos.y;
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else {
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top1 = bottom1;
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bottom1 = seam->split1->point2->pos.y;
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}
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if (seam->split2 != NULL) {
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bottom2 = seam->split2->point1->pos.y;
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if (seam->split2->point2->pos.y >= bottom2)
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top2 = seam->split2->point2->pos.y;
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else {
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top2 = bottom2;
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bottom2 = seam->split2->point2->pos.y;
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}
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}
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else {
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bottom2 = bottom1;
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top2 = top1;
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}
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array_loop(seam_pile, x) {
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this_one = (SEAM *) array_value (seam_pile, x);
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dist = seam->location - this_one->location;
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if (-SPLIT_CLOSENESS < dist &&
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dist < SPLIT_CLOSENESS &&
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seam->priority + this_one->priority < ok_split) {
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if (
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/*!tessedit_fix_sideways_chops
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|| */
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(this_one->split1->point1->pos.y >= top1
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&& this_one->split1->point2->pos.y >= top1
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|| this_one->split1->point1->pos.y <= bottom1
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&& this_one->split1->point2->pos.y <= bottom1)
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&& (this_one->split1->point1->pos.y >= top2
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&& this_one->split1->point2->pos.y >= top2
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|| this_one->split1->point1->pos.y <= bottom2
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&& this_one->split1->point2->pos.y <= bottom2)
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&& (this_one->split2 == NULL
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|| (this_one->split2->point1->pos.y >= top1
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&& this_one->split2->point2->pos.y >= top1
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|| this_one->split2->point1->pos.y <= bottom1
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&& this_one->split2->point2->pos.y <= bottom1)
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&& (this_one->split2->point1->pos.y >= top2
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&& this_one->split2->point2->pos.y >= top2
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|| this_one->split2->point1->pos.y <= bottom2
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&& this_one->split2->point2->pos.y <= bottom2))) {
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new_one = join_two_seams (seam, this_one);
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if (chop_debug > 1)
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print_seam ("Combo priority ", new_one);
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add_seam_to_queue (seam_queue, new_one, new_one->priority);
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}
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}
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}
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}
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/**********************************************************************
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* constrained_split
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*
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* Constrain this split to obey certain rules. It must not cross any
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* inner outline. It must not cut off a small chunk of the outline.
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**********************************************************************/
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INT16 constrained_split(SPLIT *split, TBLOB *blob) {
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TESSLINE *outline;
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if (is_little_chunk (split->point1, split->point2))
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return (FALSE);
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for (outline = blob->outlines; outline; outline = outline->next) {
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if (split_bounds_overlap (split, outline) &&
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crosses_outline (split->point1, split->point2, outline->loop)) {
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return (FALSE);
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}
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}
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return (TRUE);
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}
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/**********************************************************************
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* delete_seam_pile
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*
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* Delete the seams that are held in the seam pile. Destroy the splits
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* that are referenced by these seams.
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**********************************************************************/
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void delete_seam_pile(SEAM_PILE seam_pile) {
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INT16 x;
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array_loop(seam_pile, x) {
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delete_seam ((SEAM *) array_value (seam_pile, x));
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}
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array_free(seam_pile);
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}
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/**********************************************************************
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* pick_good_seam
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*
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* Find and return a good seam that will split this blob into two pieces.
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* Work from the outlines provided.
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**********************************************************************/
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SEAM *pick_good_seam(TBLOB *blob) {
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SEAM_QUEUE seam_queue;
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SEAM_PILE seam_pile;
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POINT_GROUP point_heap;
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PRIORITY priority;
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EDGEPT *edge;
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EDGEPT *points[MAX_NUM_POINTS];
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SEAM *seam = NULL;
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TESSLINE *outline;
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INT16 num_points = 0;
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#ifndef GRAPHICS_DISABLED
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if (chop_debug)
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display_splits = TRUE;
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draw_blob_edges(blob);
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#endif
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point_heap = MakeHeap (MAX_NUM_POINTS);
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for (outline = blob->outlines; outline; outline = outline->next)
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prioritize_points(outline, point_heap);
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while (HeapPop (point_heap, &priority, &edge) == OK) {
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if (num_points < MAX_NUM_POINTS)
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points[num_points++] = (EDGEPT *) edge;
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}
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FreeHeap(point_heap);
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/* Initialize queue & pile */
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create_seam_pile(seam_pile);
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create_seam_queue(seam_queue);
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try_point_pairs(points, num_points, seam_queue, &seam_pile, &seam, blob);
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try_vertical_splits(points, num_points, seam_queue, &seam_pile, &seam, blob);
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if (seam == NULL) {
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choose_best_seam(seam_queue, &seam_pile, NULL, BAD_PRIORITY, &seam, blob);
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}
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else if (seam->priority > good_split) {
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choose_best_seam (seam_queue, &seam_pile, NULL, seam->priority,
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&seam, blob);
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}
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delete_seam_queue(seam_queue);
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delete_seam_pile(seam_pile);
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if (seam) {
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if (seam->priority > ok_split) {
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delete_seam(seam);
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seam = NULL;
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}
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#ifndef GRAPHICS_DISABLED
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else if (display_splits) {
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if (seam->split1)
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mark_split (seam->split1);
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if (seam->split2)
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mark_split (seam->split2);
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if (seam->split3)
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mark_split (seam->split3);
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if (chop_debug > 1) {
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update_edge_window();
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edge_window_wait();
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}
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}
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#endif
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}
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if (chop_debug)
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display_splits = FALSE;
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return (seam);
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}
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/**********************************************************************
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* seam_priority
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*
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* Assign a full priority value to the seam.
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**********************************************************************/
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PRIORITY seam_priority(SEAM *seam, INT16 xmin, INT16 xmax) {
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PRIORITY priority;
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if (seam->split1 == NULL)
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priority = 0;
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else if (seam->split2 == NULL) {
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priority = (seam->priority +
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full_split_priority (seam->split1, xmin, xmax));
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}
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else if (seam->split3 == NULL) {
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split_outline (seam->split2->point1, seam->split2->point2);
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priority = (seam->priority +
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full_split_priority (seam->split1, xmin, xmax));
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unsplit_outlines (seam->split2->point1, seam->split2->point2);
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}
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else {
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split_outline (seam->split2->point1, seam->split2->point2);
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split_outline (seam->split3->point1, seam->split3->point2);
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priority = (seam->priority +
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full_split_priority (seam->split1, xmin, xmax));
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unsplit_outlines (seam->split3->point1, seam->split3->point2);
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unsplit_outlines (seam->split2->point1, seam->split2->point2);
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}
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return (priority);
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}
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/**********************************************************************
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* try_point_pairs
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*
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* Try all the splits that are produced by pairing critical points
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* together. See if any of them are suitable for use. Use a seam
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* queue and seam pile that have already been initialized and used.
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**********************************************************************/
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void
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try_point_pairs (EDGEPT * points[MAX_NUM_POINTS],
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INT16 num_points,
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SEAM_QUEUE seam_queue,
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SEAM_PILE * seam_pile, SEAM ** seam, TBLOB * blob) {
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INT16 x;
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INT16 y;
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SPLIT *split;
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PRIORITY priority;
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for (x = 0; x < num_points; x++) {
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for (y = x + 1; y < num_points; y++) {
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if (points[y] &&
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weighted_edgept_dist (points[x], points[y],
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x_y_weight) < split_length &&
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points[x] != points[y]->next &&
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points[y] != points[x]->next &&
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!is_exterior_point (points[x], points[y]) &&
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!is_exterior_point (points[y], points[x])) {
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split = new_split (points[x], points[y]);
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priority = partial_split_priority (split);
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choose_best_seam(seam_queue, seam_pile, split, priority, seam, blob);
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if (*seam && (*seam)->priority < good_split)
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return;
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}
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}
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}
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}
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/**********************************************************************
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* try_vertical_splits
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*
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* Try all the splits that are produced by vertical projection to see
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* if any of them are suitable for use. Use a seam queue and seam pile
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* that have already been initialized and used.
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**********************************************************************/
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void
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try_vertical_splits (EDGEPT * points[MAX_NUM_POINTS],
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INT16 num_points,
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SEAM_QUEUE seam_queue,
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SEAM_PILE * seam_pile, SEAM ** seam, TBLOB * blob) {
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EDGEPT *vertical_point = NULL;
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SPLIT *split;
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INT16 x;
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PRIORITY priority;
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TESSLINE *outline;
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for (x = 0; x < num_points; x++) {
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if (*seam != NULL && (*seam)->priority < good_split)
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return;
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vertical_point = NULL;
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for (outline = blob->outlines; outline; outline = outline->next) {
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vertical_projection_point (points[x],
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outline->loop, &vertical_point);
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}
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if (vertical_point &&
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points[x] != vertical_point->next &&
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vertical_point != points[x]->next &&
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weighted_edgept_dist (points[x], vertical_point,
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x_y_weight) < split_length) {
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split = new_split (points[x], vertical_point);
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priority = partial_split_priority (split);
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choose_best_seam(seam_queue, seam_pile, split, priority, seam, blob);
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}
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}
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}
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