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blobbox.cpp
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1 /**********************************************************************
2 * File: blobbox.cpp (Formerly blobnbox.c)
3 * Description: Code for the textord blob class.
4 * Author: Ray Smith
5 * Created: Thu Jul 30 09:08:51 BST 1992
6 *
7 * (C) Copyright 1992, Hewlett-Packard Ltd.
8 ** Licensed under the Apache License, Version 2.0 (the "License");
9 ** you may not use this file except in compliance with the License.
10 ** You may obtain a copy of the License at
11 ** http://www.apache.org/licenses/LICENSE-2.0
12 ** Unless required by applicable law or agreed to in writing, software
13 ** distributed under the License is distributed on an "AS IS" BASIS,
14 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 ** See the License for the specific language governing permissions and
16 ** limitations under the License.
17 *
18 **********************************************************************/
19
20 // Include automatically generated configuration file if running autoconf.
21 #ifdef HAVE_CONFIG_H
22 #include "config_auto.h"
23 #endif
24
25 #include "mfcpch.h"
26 #include "blobbox.h"
27 #include "helpers.h"
28
29 #define PROJECTION_MARGIN 10 //arbitrary
30 #define EXTERN
31
32 ELISTIZE (BLOBNBOX) ELIST2IZE (TO_ROW) ELISTIZE (TO_BLOCK)
33
34 // Upto 30 degrees is allowed for rotations of diacritic blobs.
35 const double kCosSmallAngle = 0.866;
36 // Min aspect ratio for a joined word to indicate an obvious flow direction.
37 const double kDefiniteAspectRatio = 2.0;
38 // Multiple of short length in perimeter to make a joined word.
39 const double kComplexShapePerimeterRatio = 1.5;
40 // Min multiple of linesize for medium-sized blobs in ReFilterBlobs.
41 const double kMinMediumSizeRatio = 0.25;
42 // Max multiple of linesize for medium-sized blobs in ReFilterBlobs.
43 const double kMaxMediumSizeRatio = 4.0;
44
45 // Rotates the box and the underlying blob.
46 void BLOBNBOX::rotate(FCOORD rotation) {
47 cblob_ptr->rotate(rotation);
48 rotate_box(rotation);
49 compute_bounding_box();
50 }
51
52 // Reflect the box in the y-axis, leaving the underlying blob untouched.
53 void BLOBNBOX::reflect_box_in_y_axis() {
54 int left = -box.right();
55 box.set_right(-box.left());
56 box.set_left(left);
57 }
58
59 // Rotates the box by the angle given by rotation.
60 // If the blob is a diacritic, then only small rotations for skew
61 // correction can be applied.
62 void BLOBNBOX::rotate_box(FCOORD rotation) {
63 if (IsDiacritic()) {
64 ASSERT_HOST(rotation.x() >= kCosSmallAngle)
65 ICOORD top_pt((box.left() + box.right()) / 2, base_char_top_);
66 ICOORD bottom_pt(top_pt.x(), base_char_bottom_);
67 top_pt.rotate(rotation);
68 base_char_top_ = top_pt.y();
69 bottom_pt.rotate(rotation);
70 base_char_bottom_ = bottom_pt.y();
71 box.rotate(rotation);
72 } else {
73 box.rotate(rotation);
74 set_diacritic_box(box);
75 }
76 }
77
78 /**********************************************************************
79 * BLOBNBOX::merge
80 *
81 * Merge this blob with the given blob, which should be after this.
82 **********************************************************************/
83 void BLOBNBOX::merge( //merge blobs
84 BLOBNBOX *nextblob //blob to join with
85 ) {
86 box += nextblob->box; //merge boxes
87 set_diacritic_box(box);
88 nextblob->joined = TRUE;
89 }
90
91
92 // Merge this with other, taking the outlines from other.
93 // Other is not deleted, but left for the caller to handle.
94 void BLOBNBOX::really_merge(BLOBNBOX* other) {
95 if (cblob_ptr != NULL && other->cblob_ptr != NULL) {
96 C_OUTLINE_IT ol_it(cblob_ptr->out_list());
97 ol_it.add_list_after(other->cblob_ptr->out_list());
98 }
99 compute_bounding_box();
100 }
101
102
103 /**********************************************************************
104 * BLOBNBOX::chop
105 *
106 * Chop this blob into equal sized pieces using the x height as a guide.
107 * The blob is not actually chopped. Instead, fake blobs are inserted
108 * with the relevant bounding boxes.
109 **********************************************************************/
110
111 void BLOBNBOX::chop( //chop blobs
112 BLOBNBOX_IT *start_it, //location of this
113 BLOBNBOX_IT *end_it, //iterator
114 FCOORD rotation, //for landscape
115 float xheight //of line
116 ) {
117 inT16 blobcount; //no of blobs
118 BLOBNBOX *newblob; //fake blob
119 BLOBNBOX *blob; //current blob
120 inT16 blobindex; //number of chop
121 inT16 leftx; //left edge of blob
122 float blobwidth; //width of each
123 float rightx; //right edge to scan
124 float ymin, ymax; //limits of new blob
125 float test_ymin, test_ymax; //limits of part blob
126 ICOORD bl, tr; //corners of box
127 BLOBNBOX_IT blob_it; //blob iterator
128
129 //get no of chops
130 blobcount = (inT16) floor (box.width () / xheight);
131 if (blobcount > 1 && cblob_ptr != NULL) {
132 //width of each
133 blobwidth = (float) (box.width () + 1) / blobcount;
134 for (blobindex = blobcount - 1, rightx = box.right ();
135 blobindex >= 0; blobindex--, rightx -= blobwidth) {
136 ymin = (float) MAX_INT32;
137 ymax = (float) -MAX_INT32;
138 blob_it = *start_it;
139 do {
140 blob = blob_it.data ();
141 find_cblob_vlimits(blob->cblob_ptr, rightx - blobwidth,
142 rightx,
143 /*rotation, */ test_ymin, test_ymax);
144 blob_it.forward ();
145 UpdateRange(test_ymin, test_ymax, &ymin, &ymax);
146 }
147 while (blob != end_it->data ());
148 if (ymin < ymax) {
149 leftx = (inT16) floor (rightx - blobwidth);
150 if (leftx < box.left ())
151 leftx = box.left (); //clip to real box
152 bl = ICOORD (leftx, (inT16) floor (ymin));
153 tr = ICOORD ((inT16) ceil (rightx), (inT16) ceil (ymax));
154 if (blobindex == 0)
155 box = TBOX (bl, tr); //change box
156 else {
157 newblob = new BLOBNBOX;
158 //box is all it has
159 newblob->box = TBOX (bl, tr);
160 //stay on current
161 newblob->base_char_top_ = tr.y();
162 newblob->base_char_bottom_ = bl.y();
163 end_it->add_after_stay_put (newblob);
164 }
165 }
166 }
167 }
168 }
169
170 // Returns the box gaps between this and its neighbours_ in an array
171 // indexed by BlobNeighbourDir.
172 void BLOBNBOX::NeighbourGaps(int gaps[BND_COUNT]) const {
173 for (int dir = 0; dir < BND_COUNT; ++dir) {
174 gaps[dir] = MAX_INT16;
175 BLOBNBOX* neighbour = neighbours_[dir];
176 if (neighbour != NULL) {
177 TBOX n_box = neighbour->bounding_box();
178 if (dir == BND_LEFT || dir == BND_RIGHT) {
179 gaps[dir] = box.x_gap(n_box);
180 } else {
181 gaps[dir] = box.y_gap(n_box);
182 }
183 }
184 }
185 }
186 // Returns the min and max horizontal and vertical gaps (from NeighbourGaps)
187 // modified so that if the max exceeds the max dimension of the blob, and
188 // the min is less, the max is replaced with the min.
189 // The objective is to catch cases where there is only a single neighbour
190 // and avoid reporting the other gap as a ridiculously large number
191 void BLOBNBOX::MinMaxGapsClipped(int* h_min, int* h_max,
192 int* v_min, int* v_max) const {
193 int max_dimension = MAX(box.width(), box.height());
194 int gaps[BND_COUNT];
195 NeighbourGaps(gaps);
196 *h_min = MIN(gaps[BND_LEFT], gaps[BND_RIGHT]);
197 *h_max = MAX(gaps[BND_LEFT], gaps[BND_RIGHT]);
198 if (*h_max > max_dimension && *h_min < max_dimension) *h_max = *h_min;
199 *v_min = MIN(gaps[BND_ABOVE], gaps[BND_BELOW]);
200 *v_max = MAX(gaps[BND_ABOVE], gaps[BND_BELOW]);
201 if (*v_max > max_dimension && *v_min < max_dimension) *v_max = *v_min;
202 }
203
204 // NULLs out any neighbours that are DeletableNoise to remove references.
205 void BLOBNBOX::CleanNeighbours() {
206 for (int dir = 0; dir < BND_COUNT; ++dir) {
207 BLOBNBOX* neighbour = neighbours_[dir];
208 if (neighbour != NULL && neighbour->DeletableNoise()) {
209 neighbours_[dir] = NULL;
210 good_stroke_neighbours_[dir] = false;
211 }
212 }
213 }
214
215 // Returns positive if there is at least one side neighbour that has a similar
216 // stroke width and is not on the other side of a rule line.
217 int BLOBNBOX::GoodTextBlob() const {
218 int score = 0;
219 for (int dir = 0; dir < BND_COUNT; ++dir) {
220 BlobNeighbourDir bnd = static_cast<BlobNeighbourDir>(dir);
221 if (good_stroke_neighbour(bnd))
222 ++score;
223 }
224 return score;
225 }
226
227 // Returns the number of side neighbours that are of type BRT_NOISE.
228 int BLOBNBOX::NoisyNeighbours() const {
229 int count = 0;
230 for (int dir = 0; dir < BND_COUNT; ++dir) {
231 BlobNeighbourDir bnd = static_cast<BlobNeighbourDir>(dir);
232 BLOBNBOX* blob = neighbour(bnd);
233 if (blob != NULL && blob->region_type() == BRT_NOISE)
234 ++count;
235 }
236 return count;
237 }
238
239 // Returns true, and sets vert_possible/horz_possible if the blob has some
240 // feature that makes it individually appear to flow one way.
241 // eg if it has a high aspect ratio, yet has a complex shape, such as a
242 // joined word in Latin, Arabic, or Hindi, rather than being a -, I, l, 1 etc.
243 bool BLOBNBOX::DefiniteIndividualFlow() {
244 int box_perimeter = 2 * (box.height() + box.width());
245 if (box.width() > box.height() * kDefiniteAspectRatio) {
246 // Attempt to distinguish a wide joined word from a dash.
247 // If it is a dash, then its perimeter is approximately
248 // 2 * (box width + stroke width), but more if the outline is noisy,
249 // so perimeter - 2*(box width + stroke width) should be close to zero.
250 // A complex shape such as a joined word should have a much larger value.
251 int perimeter = cblob()->perimeter();
252 if (vert_stroke_width() > 0)
253 perimeter -= 2 * vert_stroke_width();
254 else
255 perimeter -= 4 * cblob()->area() / perimeter;
256 perimeter -= 2 * box.width();
257 // Use a multiple of the box perimeter as a threshold.
258 if (perimeter > kComplexShapePerimeterRatio * box_perimeter) {
259 set_vert_possible(false);
260 set_horz_possible(true);
261 return true;
262 }
263 }
264 if (box.height() > box.width() * kDefiniteAspectRatio) {
265 // As above, but for a putative vertical word vs a I/1/l.
266 int perimeter = cblob()->perimeter();
267 if (horz_stroke_width() > 0)
268 perimeter -= 2 * horz_stroke_width();
269 else
270 perimeter -= 4 * cblob()->area() / perimeter;
271 perimeter -= 2 * box.height();
272 if (perimeter > kComplexShapePerimeterRatio * box_perimeter) {
273 set_vert_possible(true);
274 set_horz_possible(false);
275 return true;
276 }
277 }
278 return false;
279 }
280
281 // Returns true if there is no tabstop violation in merging this and other.
282 bool BLOBNBOX::ConfirmNoTabViolation(const BLOBNBOX& other) const {
283 if (box.left() < other.box.left() && box.left() < other.left_rule_)
284 return false;
285 if (other.box.left() < box.left() && other.box.left() < left_rule_)
286 return false;
287 if (box.right() > other.box.right() && box.right() > other.right_rule_)
288 return false;
289 if (other.box.right() > box.right() && other.box.right() > right_rule_)
290 return false;
291 return true;
292 }
293
294 // Returns true if other has a similar stroke width to this.
295 bool BLOBNBOX::MatchingStrokeWidth(const BLOBNBOX& other,
296 double fractional_tolerance,
297 double constant_tolerance) const {
298 // The perimeter-based width is used as a backup in case there is
299 // no information in the blob.
300 double p_width = area_stroke_width();
301 double n_p_width = other.area_stroke_width();
302 float h_tolerance = horz_stroke_width_ * fractional_tolerance
303 + constant_tolerance;
304 float v_tolerance = vert_stroke_width_ * fractional_tolerance
305 + constant_tolerance;
306 double p_tolerance = p_width * fractional_tolerance
307 + constant_tolerance;
308 bool h_zero = horz_stroke_width_ == 0.0f || other.horz_stroke_width_ == 0.0f;
309 bool v_zero = vert_stroke_width_ == 0.0f || other.vert_stroke_width_ == 0.0f;
310 bool h_ok = !h_zero && NearlyEqual(horz_stroke_width_,
311 other.horz_stroke_width_, h_tolerance);
312 bool v_ok = !v_zero && NearlyEqual(vert_stroke_width_,
313 other.vert_stroke_width_, v_tolerance);
314 bool p_ok = h_zero && v_zero && NearlyEqual(p_width, n_p_width, p_tolerance);
315 // For a match, at least one of the horizontal and vertical widths
316 // must match, and the other one must either match or be zero.
317 // Only if both are zero will we look at the perimeter metric.
318 return p_ok || ((v_ok || h_ok) && (h_ok || h_zero) && (v_ok || v_zero));
319 }
320
321 // Returns a bounding box of the outline contained within the
322 // given horizontal range.
323 TBOX BLOBNBOX::BoundsWithinLimits(int left, int right) {
324 FCOORD no_rotation(1.0f, 0.0f);
325 float top = box.top();
326 float bottom = box.bottom();
327 if (cblob_ptr != NULL) {
328 find_cblob_limits(cblob_ptr, static_cast<float>(left),
329 static_cast<float>(right), no_rotation,
330 bottom, top);
331 }
332
333 if (top < bottom) {
334 top = box.top();
335 bottom = box.bottom();
336 }
337 FCOORD bot_left(left, bottom);
338 FCOORD top_right(right, top);
339 TBOX shrunken_box(bot_left);
340 TBOX shrunken_box2(top_right);
341 shrunken_box += shrunken_box2;
342 return shrunken_box;
343 }
344
345 // Helper to call CleanNeighbours on all blobs on the list.
346 void BLOBNBOX::CleanNeighbours(BLOBNBOX_LIST* blobs) {
347 BLOBNBOX_IT blob_it(blobs);
348 for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
349 blob_it.data()->CleanNeighbours();
350 }
351 }
352
353 // Helper to delete all the deletable blobs on the list.
354 void BLOBNBOX::DeleteNoiseBlobs(BLOBNBOX_LIST* blobs) {
355 BLOBNBOX_IT blob_it(blobs);
356 for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
357 BLOBNBOX* blob = blob_it.data();
358 if (blob->DeletableNoise()) {
359 delete blob->cblob();
360 delete blob_it.extract();
361 }
362 }
363 }
364
365 #ifndef GRAPHICS_DISABLED
366 // Helper to draw all the blobs on the list in the given body_colour,
367 // with child outlines in the child_colour.
368 void BLOBNBOX::PlotBlobs(BLOBNBOX_LIST* list,
369 ScrollView::Color body_colour,
370 ScrollView::Color child_colour,
371 ScrollView* win) {
372 BLOBNBOX_IT it(list);
373 for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
374 it.data()->plot(win, body_colour, child_colour);
375 }
376 }
377
378 // Helper to draw only DeletableNoise blobs (unowned, BRT_NOISE) on the
379 // given list in the given body_colour, with child outlines in the
380 // child_colour.
381 void BLOBNBOX::PlotNoiseBlobs(BLOBNBOX_LIST* list,
382 ScrollView::Color body_colour,
383 ScrollView::Color child_colour,
384 ScrollView* win) {
385 BLOBNBOX_IT it(list);
386 for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
387 BLOBNBOX* blob = it.data();
388 if (blob->DeletableNoise())
389 blob->plot(win, body_colour, child_colour);
390 }
391 }
392
393 ScrollView::Color BLOBNBOX::TextlineColor(BlobRegionType region_type,
394 BlobTextFlowType flow_type) {
395 switch (region_type) {
396 case BRT_HLINE:
397 return ScrollView::BROWN;
398 case BRT_VLINE:
399 return ScrollView::DARK_GREEN;
400 case BRT_RECTIMAGE:
401 return ScrollView::RED;
402 case BRT_POLYIMAGE:
403 return ScrollView::ORANGE;
404 case BRT_UNKNOWN:
405 return flow_type == BTFT_NONTEXT ? ScrollView::CYAN : ScrollView::WHITE;
406 case BRT_VERT_TEXT:
407 if (flow_type == BTFT_STRONG_CHAIN || flow_type == BTFT_TEXT_ON_IMAGE)
408 return ScrollView::GREEN;
409 if (flow_type == BTFT_CHAIN)
410 return ScrollView::LIME_GREEN;
411 return ScrollView::YELLOW;
412 case BRT_TEXT:
413 if (flow_type == BTFT_STRONG_CHAIN)
414 return ScrollView::BLUE;
415 if (flow_type == BTFT_TEXT_ON_IMAGE)
416 return ScrollView::LIGHT_BLUE;
417 if (flow_type == BTFT_CHAIN)
418 return ScrollView::MEDIUM_BLUE;
419 if (flow_type == BTFT_LEADER)
420 return ScrollView::WHEAT;
421 if (flow_type == BTFT_NONTEXT)
422 return ScrollView::PINK;
423 return ScrollView::MAGENTA;
424 default:
425 return ScrollView::GREY;
426 }
427 }
428
429 // Keep in sync with BlobRegionType.
430 ScrollView::Color BLOBNBOX::BoxColor() const {
431 return TextlineColor(region_type_, flow_);
432 }
433
434 void BLOBNBOX::plot(ScrollView* window, // window to draw in
435 ScrollView::Color blob_colour, // for outer bits
436 ScrollView::Color child_colour) { // for holes
437 if (cblob_ptr != NULL)
438 cblob_ptr->plot(window, blob_colour, child_colour);
439 }
440 #endif
441 /**********************************************************************
442 * find_cblob_limits
443 *
444 * Scan the outlines of the cblob to locate the y min and max
445 * between the given x limits.
446 **********************************************************************/
447
448 void find_cblob_limits( //get y limits
449 C_BLOB *blob, //blob to search
450 float leftx, //x limits
451 float rightx,
452 FCOORD rotation, //for landscape
453 float &ymin, //output y limits
454 float &ymax) {
455 inT16 stepindex; //current point
456 ICOORD pos; //current coords
457 ICOORD vec; //rotated step
458 C_OUTLINE *outline; //current outline
459 //outlines
460 C_OUTLINE_IT out_it = blob->out_list ();
461
462 ymin = (float) MAX_INT32;
463 ymax = (float) -MAX_INT32;
464 for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
465 outline = out_it.data ();
466 pos = outline->start_pos (); //get coords
467 pos.rotate (rotation);
468 for (stepindex = 0; stepindex < outline->pathlength (); stepindex++) {
469 //inside
470 if (pos.x () >= leftx && pos.x () <= rightx) {
471 UpdateRange(pos.y(), &ymin, &ymax);
472 }
473 vec = outline->step (stepindex);
474 vec.rotate (rotation);
475 pos += vec; //move to next
476 }
477 }
478 }
479
480
481 /**********************************************************************
482 * find_cblob_vlimits
483 *
484 * Scan the outlines of the cblob to locate the y min and max
485 * between the given x limits.
486 **********************************************************************/
487
488 void find_cblob_vlimits( //get y limits
489 C_BLOB *blob, //blob to search
490 float leftx, //x limits
491 float rightx,
492 float &ymin, //output y limits
493 float &ymax) {
494 inT16 stepindex; //current point
495 ICOORD pos; //current coords
496 ICOORD vec; //rotated step
497 C_OUTLINE *outline; //current outline
498 //outlines
499 C_OUTLINE_IT out_it = blob->out_list ();
500
501 ymin = (float) MAX_INT32;
502 ymax = (float) -MAX_INT32;
503 for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
504 outline = out_it.data ();
505 pos = outline->start_pos (); //get coords
506 for (stepindex = 0; stepindex < outline->pathlength (); stepindex++) {
507 //inside
508 if (pos.x () >= leftx && pos.x () <= rightx) {
509 UpdateRange(pos.y(), &ymin, &ymax);
510 }
511 vec = outline->step (stepindex);
512 pos += vec; //move to next
513 }
514 }
515 }
516
517
518 /**********************************************************************
519 * find_cblob_hlimits
520 *
521 * Scan the outlines of the cblob to locate the x min and max
522 * between the given y limits.
523 **********************************************************************/
524
525 void find_cblob_hlimits( //get x limits
526 C_BLOB *blob, //blob to search
527 float bottomy, //y limits
528 float topy,
529 float &xmin, //output x limits
530 float &xmax) {
531 inT16 stepindex; //current point
532 ICOORD pos; //current coords
533 ICOORD vec; //rotated step
534 C_OUTLINE *outline; //current outline
535 //outlines
536 C_OUTLINE_IT out_it = blob->out_list ();
537
538 xmin = (float) MAX_INT32;
539 xmax = (float) -MAX_INT32;
540 for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
541 outline = out_it.data ();
542 pos = outline->start_pos (); //get coords
543 for (stepindex = 0; stepindex < outline->pathlength (); stepindex++) {
544 //inside
545 if (pos.y () >= bottomy && pos.y () <= topy) {
546 UpdateRange(pos.x(), &xmin, &xmax);
547 }
548 vec = outline->step (stepindex);
549 pos += vec; //move to next
550 }
551 }
552 }
553
554 /**********************************************************************
555 * crotate_cblob
556 *
557 * Rotate the copy by the given vector and return a C_BLOB.
558 **********************************************************************/
559
560 C_BLOB *crotate_cblob( //rotate it
561 C_BLOB *blob, //blob to search
562 FCOORD rotation //for landscape
563 ) {
564 C_OUTLINE_LIST out_list; //output outlines
565 //input outlines
566 C_OUTLINE_IT in_it = blob->out_list ();
567 //output outlines
568 C_OUTLINE_IT out_it = &out_list;
569
570 for (in_it.mark_cycle_pt (); !in_it.cycled_list (); in_it.forward ()) {
571 out_it.add_after_then_move (new C_OUTLINE (in_it.data (), rotation));
572 }
573 return new C_BLOB (&out_list);
574 }
575
576
577 /**********************************************************************
578 * box_next
579 *
580 * Compute the bounding box of this blob with merging of x overlaps
581 * but no pre-chopping.
582 * Then move the iterator on to the start of the next blob.
583 **********************************************************************/
584
585 TBOX box_next( //get bounding box
586 BLOBNBOX_IT *it //iterator to blobds
587 ) {
588 BLOBNBOX *blob; //current blob
589 TBOX result; //total box
590
591 blob = it->data ();
592 result = blob->bounding_box ();
593 do {
594 it->forward ();
595 blob = it->data ();
596 if (blob->cblob() == NULL)
597 //was pre-chopped
598 result += blob->bounding_box ();
599 }
600 //until next real blob
601 while ((blob->cblob() == NULL) || blob->joined_to_prev());
602 return result;
603 }
604
605
606 /**********************************************************************
607 * box_next_pre_chopped
608 *
609 * Compute the bounding box of this blob with merging of x overlaps
610 * but WITH pre-chopping.
611 * Then move the iterator on to the start of the next pre-chopped blob.
612 **********************************************************************/
613
614 TBOX box_next_pre_chopped( //get bounding box
615 BLOBNBOX_IT *it //iterator to blobds
616 ) {
617 BLOBNBOX *blob; //current blob
618 TBOX result; //total box
619
620 blob = it->data ();
621 result = blob->bounding_box ();
622 do {
623 it->forward ();
624 blob = it->data ();
625 }
626 //until next real blob
627 while (blob->joined_to_prev ());
628 return result;
629 }
630
631
632 /**********************************************************************
633 * TO_ROW::TO_ROW
634 *
635 * Constructor to make a row from a blob.
636 **********************************************************************/
637
638 TO_ROW::TO_ROW ( //constructor
639 BLOBNBOX * blob, //first blob
640 float top, //corrected top
641 float bottom, //of row
642 float row_size //ideal
643 ) {
644 clear();
645 y_min = bottom;
646 y_max = top;
647 initial_y_min = bottom;
648
649 float diff; //in size
650 BLOBNBOX_IT it = &blobs; //list of blobs
651
652 it.add_to_end (blob);
653 diff = top - bottom - row_size;
654 if (diff > 0) {
655 y_max -= diff / 2;
656 y_min += diff / 2;
657 }
658 //very small object
659 else if ((top - bottom) * 3 < row_size) {
660 diff = row_size / 3 + bottom - top;
661 y_max += diff / 2;
662 y_min -= diff / 2;
663 }
664 }
665
666
667 /**********************************************************************
668 * TO_ROW:add_blob
669 *
670 * Add the blob to the end of the row.
671 **********************************************************************/
672
673 void TO_ROW::add_blob( //constructor
674 BLOBNBOX *blob, //first blob
675 float top, //corrected top
676 float bottom, //of row
677 float row_size //ideal
678 ) {
679 float allowed; //allowed expansion
680 float available; //expansion
681 BLOBNBOX_IT it = &blobs; //list of blobs
682
683 it.add_to_end (blob);
684 allowed = row_size + y_min - y_max;
685 if (allowed > 0) {
686 available = top > y_max ? top - y_max : 0;
687 if (bottom < y_min)
688 //total available
689 available += y_min - bottom;
690 if (available > 0) {
691 available += available; //do it gradually
692 if (available < allowed)
693 available = allowed;
694 if (bottom < y_min)
695 y_min -= (y_min - bottom) * allowed / available;
696 if (top > y_max)
697 y_max += (top - y_max) * allowed / available;
698 }
699 }
700 }
701
702
703 /**********************************************************************
704 * TO_ROW:insert_blob
705 *
706 * Add the blob to the row in the correct position.
707 **********************************************************************/
708
709 void TO_ROW::insert_blob( //constructor
710 BLOBNBOX *blob //first blob
711 ) {
712 BLOBNBOX_IT it = &blobs; //list of blobs
713
714 if (it.empty ())
715 it.add_before_then_move (blob);
716 else {
717 it.mark_cycle_pt ();
718 while (!it.cycled_list ()
719 && it.data ()->bounding_box ().left () <=
720 blob->bounding_box ().left ())
721 it.forward ();
722 if (it.cycled_list ())
723 it.add_to_end (blob);
724 else
725 it.add_before_stay_put (blob);
726 }
727 }
728
729
730 /**********************************************************************
731 * TO_ROW::compute_vertical_projection
732 *
733 * Compute the vertical projection of a TO_ROW from its blobs.
734 **********************************************************************/
735
736 void TO_ROW::compute_vertical_projection() { //project whole row
737 TBOX row_box; //bound of row
738 BLOBNBOX *blob; //current blob
739 TBOX blob_box; //bounding box
740 BLOBNBOX_IT blob_it = blob_list ();
741
742 if (blob_it.empty ())
743 return;
744 row_box = blob_it.data ()->bounding_box ();
745 for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ())
746 row_box += blob_it.data ()->bounding_box ();
747
748 projection.set_range (row_box.left () - PROJECTION_MARGIN,
749 row_box.right () + PROJECTION_MARGIN);
750 projection_left = row_box.left () - PROJECTION_MARGIN;
751 projection_right = row_box.right () + PROJECTION_MARGIN;
752 for (blob_it.mark_cycle_pt (); !blob_it.cycled_list (); blob_it.forward ()) {
753 blob = blob_it.data();
754 if (blob->cblob() != NULL)
755 vertical_cblob_projection(blob->cblob(), &projection);
756 }
757 }
758
759
760 /**********************************************************************
761 * TO_ROW::clear
762 *
763 * Zero out all scalar members.
764 **********************************************************************/
765 void TO_ROW::clear() {
766 all_caps = 0;
767 used_dm_model = 0;
768 projection_left = 0;
769 projection_right = 0;
770 pitch_decision = PITCH_DUNNO;
771 fixed_pitch = 0.0;
772 fp_space = 0.0;
773 fp_nonsp = 0.0;
774 pr_space = 0.0;
775 pr_nonsp = 0.0;
776 spacing = 0.0;
777 xheight = 0.0;
778 xheight_evidence = 0;
779 body_size = 0.0;
780 ascrise = 0.0;
781 descdrop = 0.0;
782 min_space = 0;
783 max_nonspace = 0;
784 space_threshold = 0;
785 kern_size = 0.0;
786 space_size = 0.0;
787 y_min = 0.0;
788 y_max = 0.0;
789 initial_y_min = 0.0;
790 m = 0.0;
791 c = 0.0;
792 error = 0.0;
793 para_c = 0.0;
794 para_error = 0.0;
795 y_origin = 0.0;
796 credibility = 0.0;
797 num_repeated_sets_ = -1;
798 }
799
800
801 /**********************************************************************
802 * vertical_cblob_projection
803 *
804 * Compute the vertical projection of a cblob from its outlines
805 * and add to the given STATS.
806 **********************************************************************/
807
808 void vertical_cblob_projection( //project outlines
809 C_BLOB *blob, //blob to project
810 STATS *stats //output
811 ) {
812 //outlines of blob
813 C_OUTLINE_IT out_it = blob->out_list ();
814
815 for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
816 vertical_coutline_projection (out_it.data (), stats);
817 }
818 }
819
820
821 /**********************************************************************
822 * vertical_coutline_projection
823 *
824 * Compute the vertical projection of a outline from its outlines
825 * and add to the given STATS.
826 **********************************************************************/
827
828 void vertical_coutline_projection( //project outlines
829 C_OUTLINE *outline, //outline to project
830 STATS *stats //output
831 ) {
832 ICOORD pos; //current point
833 ICOORD step; //edge step
834 inT32 length; //of outline
835 inT16 stepindex; //current step
836 C_OUTLINE_IT out_it = outline->child ();
837
838 pos = outline->start_pos ();
839 length = outline->pathlength ();
840 for (stepindex = 0; stepindex < length; stepindex++) {
841 step = outline->step (stepindex);
842 if (step.x () > 0) {
843 stats->add (pos.x (), -pos.y ());
844 } else if (step.x () < 0) {
845 stats->add (pos.x () - 1, pos.y ());
846 }
847 pos += step;
848 }
849
850 for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
851 vertical_coutline_projection (out_it.data (), stats);
852 }
853 }
854
855
856 /**********************************************************************
857 * TO_BLOCK::TO_BLOCK
858 *
859 * Constructor to make a TO_BLOCK from a real block.
860 **********************************************************************/
861
862 TO_BLOCK::TO_BLOCK( //make a block
863 BLOCK *src_block //real block
864 ) {
865 clear();
866 block = src_block;
867 }
868
869 static void clear_blobnboxes(BLOBNBOX_LIST* boxes) {
870 BLOBNBOX_IT it = boxes;
871 // A BLOBNBOX generally doesn't own its blobs, so if they do, you
872 // have to delete them explicitly.
873 for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
874 BLOBNBOX* box = it.data();
875 if (box->cblob() != NULL)
876 delete box->cblob();
877 }
878 }
879
880 /**********************************************************************
881 * TO_BLOCK::clear
882 *
883 * Zero out all scalar members.
884 **********************************************************************/
885 void TO_BLOCK::clear() {
886 block = NULL;
887 pitch_decision = PITCH_DUNNO;
888 line_spacing = 0.0;
889 line_size = 0.0;
890 max_blob_size = 0.0;
891 baseline_offset = 0.0;
892 xheight = 0.0;
893 fixed_pitch = 0.0;
894 kern_size = 0.0;
895 space_size = 0.0;
896 min_space = 0;
897 max_nonspace = 0;
898 fp_space = 0.0;
899 fp_nonsp = 0.0;
900 pr_space = 0.0;
901 pr_nonsp = 0.0;
902 key_row = NULL;
903 }
904
905
906 TO_BLOCK::~TO_BLOCK() {
907 // Any residual BLOBNBOXes at this stage own their blobs, so delete them.
908 clear_blobnboxes(&blobs);
909 clear_blobnboxes(&underlines);
910 clear_blobnboxes(&noise_blobs);
911 clear_blobnboxes(&small_blobs);
912 clear_blobnboxes(&large_blobs);
913 }
914
915 // Helper function to divide the input blobs over noise, small, medium
916 // and large lists. Blobs small in height and (small in width or large in width)
917 // go in the noise list. Dash (-) candidates go in the small list, and
918 // medium and large are by height.
919 // SIDE-EFFECT: reset all blobs to initial state by calling Init().
920 static void SizeFilterBlobs(int min_height, int max_height,
921 BLOBNBOX_LIST* src_list,
922 BLOBNBOX_LIST* noise_list,
923 BLOBNBOX_LIST* small_list,
924 BLOBNBOX_LIST* medium_list,
925 BLOBNBOX_LIST* large_list) {
926 BLOBNBOX_IT noise_it(noise_list);
927 BLOBNBOX_IT small_it(small_list);
928 BLOBNBOX_IT medium_it(medium_list);
929 BLOBNBOX_IT large_it(large_list);
930 for (BLOBNBOX_IT src_it(src_list); !src_it.empty(); src_it.forward()) {
931 BLOBNBOX* blob = src_it.extract();
932 blob->ReInit();
933 int width = blob->bounding_box().width();
934 int height = blob->bounding_box().height();
935 if (height < min_height &&
936 (width < min_height || width > max_height))
937 noise_it.add_after_then_move(blob);
938 else if (height > max_height)
939 large_it.add_after_then_move(blob);
940 else if (height < min_height)
941 small_it.add_after_then_move(blob);
942 else
943 medium_it.add_after_then_move(blob);
944 }
945 }
946
947 // Reorganize the blob lists with a different definition of small, medium
948 // and large, compared to the original definition.
949 // Height is still the primary filter key, but medium width blobs of small
950 // height become small, and very wide blobs of small height stay noise, along
951 // with small dot-shaped blobs.
952 void TO_BLOCK::ReSetAndReFilterBlobs() {
953 int min_height = IntCastRounded(kMinMediumSizeRatio * line_size);
954 int max_height = IntCastRounded(kMaxMediumSizeRatio * line_size);
955 BLOBNBOX_LIST noise_list;
956 BLOBNBOX_LIST small_list;
957 BLOBNBOX_LIST medium_list;
958 BLOBNBOX_LIST large_list;
959 SizeFilterBlobs(min_height, max_height, &blobs,
960 &noise_list, &small_list, &medium_list, &large_list);
961 SizeFilterBlobs(min_height, max_height, &large_blobs,
962 &noise_list, &small_list, &medium_list, &large_list);
963 SizeFilterBlobs(min_height, max_height, &small_blobs,
964 &noise_list, &small_list, &medium_list, &large_list);
965 SizeFilterBlobs(min_height, max_height, &noise_blobs,
966 &noise_list, &small_list, &medium_list, &large_list);
967 BLOBNBOX_IT blob_it(&blobs);
968 blob_it.add_list_after(&medium_list);
969 blob_it.set_to_list(&large_blobs);
970 blob_it.add_list_after(&large_list);
971 blob_it.set_to_list(&small_blobs);
972 blob_it.add_list_after(&small_list);
973 blob_it.set_to_list(&noise_blobs);
974 blob_it.add_list_after(&noise_list);
975 }
976
977 // Deletes noise blobs from all lists where not owned by a ColPartition.
978 void TO_BLOCK::DeleteUnownedNoise() {
979 BLOBNBOX::CleanNeighbours(&blobs);
980 BLOBNBOX::CleanNeighbours(&small_blobs);
981 BLOBNBOX::CleanNeighbours(&noise_blobs);
982 BLOBNBOX::CleanNeighbours(&large_blobs);
983 BLOBNBOX::DeleteNoiseBlobs(&blobs);
984 BLOBNBOX::DeleteNoiseBlobs(&small_blobs);
985 BLOBNBOX::DeleteNoiseBlobs(&noise_blobs);
986 BLOBNBOX::DeleteNoiseBlobs(&large_blobs);
987 }
988
989 #ifndef GRAPHICS_DISABLED
990 // Draw the noise blobs from all lists in red.
991 void TO_BLOCK::plot_noise_blobs(ScrollView* win) {
992 BLOBNBOX::PlotNoiseBlobs(&noise_blobs, ScrollView::RED, ScrollView::RED, win);
993 BLOBNBOX::PlotNoiseBlobs(&small_blobs, ScrollView::RED, ScrollView::RED, win);
994 BLOBNBOX::PlotNoiseBlobs(&large_blobs, ScrollView::RED, ScrollView::RED, win);
995 BLOBNBOX::PlotNoiseBlobs(&blobs, ScrollView::RED, ScrollView::RED, win);
996 }
997
998 // Draw the blobs on the various lists in the block in different colors.
999 void TO_BLOCK::plot_graded_blobs(ScrollView* win) {
1000 BLOBNBOX::PlotBlobs(&noise_blobs, ScrollView::CORAL, ScrollView::BLUE, win);
1001 BLOBNBOX::PlotBlobs(&small_blobs, ScrollView::GOLDENROD, ScrollView::YELLOW,
1002 win);
1003 BLOBNBOX::PlotBlobs(&large_blobs, ScrollView::DARK_GREEN, ScrollView::YELLOW,
1004 win);
1005 BLOBNBOX::PlotBlobs(&blobs, ScrollView::WHITE, ScrollView::BROWN, win);
1006 }
1007
1008 /**********************************************************************
1009 * plot_blob_list
1010 *
1011 * Draw a list of blobs.
1012 **********************************************************************/
1013
1014 void plot_blob_list(ScrollView* win, // window to draw in
1015 BLOBNBOX_LIST *list, // blob list
1016 ScrollView::Color body_colour, // colour to draw
1017 ScrollView::Color child_colour) { // colour of child
1018 BLOBNBOX_IT it = list;
1019 for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
1020 it.data()->plot(win, body_colour, child_colour);
1021 }
1022 }
1023 #endif // GRAPHICS_DISABLED