forked from dmtx/libdmtx
-
Notifications
You must be signed in to change notification settings - Fork 0
/
dmtxregion.c
1916 lines (1625 loc) · 52 KB
/
dmtxregion.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/**
* libdmtx - Data Matrix Encoding/Decoding Library
* Copyright 2008, 2009 Mike Laughton. All rights reserved.
* Copyright 2012-2016 Vadim A. Misbakh-Soloviov. All rights reserved.
* Copyright 2016 Tim Zaman. All rights reserved.
*
* See LICENSE file in the main project directory for full
* terms of use and distribution.
*
* Contact:
* Vadim A. Misbakh-Soloviov <[email protected]>
* Mike Laughton <[email protected]>
*
* \file dmtxregion.c
* \brief Detect barcode regions
*/
#define DMTX_HOUGH_RES 180
/**
* \brief Create copy of existing region struct
* \param None
* \return Initialized DmtxRegion struct
*/
extern DmtxRegion *
dmtxRegionCreate(DmtxRegion *reg)
{
DmtxRegion *regCopy;
regCopy = (DmtxRegion *)malloc(sizeof(DmtxRegion));
if(regCopy == NULL)
return NULL;
memcpy(regCopy, reg, sizeof(DmtxRegion));
return regCopy;
}
/**
* \brief Destroy region struct
* \param reg
* \return void
*/
extern DmtxPassFail
dmtxRegionDestroy(DmtxRegion **reg)
{
if(reg == NULL || *reg == NULL)
return DmtxFail;
free(*reg);
*reg = NULL;
return DmtxPass;
}
/**
* \brief Find next barcode region
* \param dec Pointer to DmtxDecode information struct
* \param timeout Pointer to timeout time (NULL if none)
* \return Detected region (if found)
*/
extern DmtxRegion *
dmtxRegionFindNext(DmtxDecode *dec, DmtxTime *timeout)
{
int locStatus;
DmtxPixelLoc loc;
DmtxRegion *reg;
/* Continue until we find a region or run out of chances */
for(;;) {
locStatus = PopGridLocation(&(dec->grid), &loc);
if(locStatus == DmtxRangeEnd)
break;
/* Scan location for presence of valid barcode region */
reg = dmtxRegionScanPixel(dec, loc.X, loc.Y);
if(reg != NULL)
return reg;
/* Ran out of time? */
if(timeout != NULL && dmtxTimeExceeded(*timeout))
break;
}
return NULL;
}
/**
* \brief Scan individual pixel for presence of barcode edge
* \param dec Pointer to DmtxDecode information struct
* \param loc Pixel location
* \return Detected region (if any)
*/
extern DmtxRegion *
dmtxRegionScanPixel(DmtxDecode *dec, int x, int y)
{
unsigned char *cache;
DmtxRegion reg;
DmtxPointFlow flowBegin;
DmtxPixelLoc loc;
loc.X = x;
loc.Y = y;
cache = dmtxDecodeGetCache(dec, loc.X, loc.Y);
if(cache == NULL)
return NULL;
if((int)(*cache & 0x80) != 0x00)
return NULL;
/* Test for presence of any reasonable edge at this location */
flowBegin = MatrixRegionSeekEdge(dec, loc);
if(flowBegin.mag < (int)(dec->edgeThresh * 7.65 + 0.5))
return NULL;
memset(®, 0x00, sizeof(DmtxRegion));
/* Determine barcode orientation */
if(MatrixRegionOrientation(dec, ®, flowBegin) == DmtxFail)
return NULL;
if(dmtxRegionUpdateXfrms(dec, ®) == DmtxFail)
return NULL;
/* Define top edge */
if(MatrixRegionAlignCalibEdge(dec, ®, DmtxEdgeTop) == DmtxFail)
return NULL;
if(dmtxRegionUpdateXfrms(dec, ®) == DmtxFail)
return NULL;
/* Define right edge */
if(MatrixRegionAlignCalibEdge(dec, ®, DmtxEdgeRight) == DmtxFail)
return NULL;
if(dmtxRegionUpdateXfrms(dec, ®) == DmtxFail)
return NULL;
CALLBACK_MATRIX(®);
/* Calculate the best fitting symbol size */
if(MatrixRegionFindSize(dec, ®) == DmtxFail)
return NULL;
/* Found a valid matrix region */
return dmtxRegionCreate(®);
}
/**
*
*
*/
static DmtxPointFlow
MatrixRegionSeekEdge(DmtxDecode *dec, DmtxPixelLoc loc)
{
int i;
int strongIdx;
int channelCount;
DmtxPointFlow flow, flowPlane[3];
DmtxPointFlow flowPos, flowPosBack;
DmtxPointFlow flowNeg, flowNegBack;
channelCount = dec->image->channelCount;
/* Find whether red, green, or blue shows the strongest edge */
strongIdx = 0;
for(i = 0; i < channelCount; i++) {
flowPlane[i] = GetPointFlow(dec, i, loc, dmtxNeighborNone);
if(i > 0 && flowPlane[i].mag > flowPlane[strongIdx].mag)
strongIdx = i;
}
if(flowPlane[strongIdx].mag < 10)
return dmtxBlankEdge;
flow = flowPlane[strongIdx];
flowPos = FindStrongestNeighbor(dec, flow, +1);
flowNeg = FindStrongestNeighbor(dec, flow, -1);
if(flowPos.mag != 0 && flowNeg.mag != 0) {
flowPosBack = FindStrongestNeighbor(dec, flowPos, -1);
flowNegBack = FindStrongestNeighbor(dec, flowNeg, +1);
if(flowPos.arrive == (flowPosBack.arrive+4)%8 &&
flowNeg.arrive == (flowNegBack.arrive+4)%8) {
flow.arrive = dmtxNeighborNone;
CALLBACK_POINT_PLOT(flow.loc, 1, 1, 1);
return flow;
}
}
return dmtxBlankEdge;
}
/**
*
*
*/
static DmtxPassFail
MatrixRegionOrientation(DmtxDecode *dec, DmtxRegion *reg, DmtxPointFlow begin)
{
int cross;
int minArea;
int scale;
int symbolShape;
int maxDiagonal;
DmtxPassFail err;
DmtxBestLine line1x, line2x;
DmtxBestLine line2n, line2p;
DmtxFollow fTmp;
if(dec->sizeIdxExpected == DmtxSymbolSquareAuto ||
(dec->sizeIdxExpected >= DmtxSymbol10x10 &&
dec->sizeIdxExpected <= DmtxSymbol144x144))
symbolShape = DmtxSymbolSquareAuto;
else if(dec->sizeIdxExpected == DmtxSymbolRectAuto ||
(dec->sizeIdxExpected >= DmtxSymbol8x18 &&
dec->sizeIdxExpected <= DmtxSymbol16x48))
symbolShape = DmtxSymbolRectAuto;
else
symbolShape = DmtxSymbolShapeAuto;
if(dec->edgeMax != DmtxUndefined) {
if(symbolShape == DmtxSymbolRectAuto)
maxDiagonal = (int)(1.23 * dec->edgeMax + 0.5); /* sqrt(5/4) + 10% */
else
maxDiagonal = (int)(1.56 * dec->edgeMax + 0.5); /* sqrt(2) + 10% */
}
else {
maxDiagonal = DmtxUndefined;
}
/* Follow to end in both directions */
err = TrailBlazeContinuous(dec, reg, begin, maxDiagonal);
if(err == DmtxFail || reg->stepsTotal < 40) {
TrailClear(dec, reg, 0x40);
return DmtxFail;
}
/* Filter out region candidates that are smaller than expected */
if(dec->edgeMin != DmtxUndefined) {
scale = dmtxDecodeGetProp(dec, DmtxPropScale);
if(symbolShape == DmtxSymbolSquareAuto)
minArea = (dec->edgeMin * dec->edgeMin)/(scale * scale);
else
minArea = (2 * dec->edgeMin * dec->edgeMin)/(scale * scale);
if((reg->boundMax.X - reg->boundMin.X) * (reg->boundMax.Y - reg->boundMin.Y) < minArea) {
TrailClear(dec, reg, 0x40);
return DmtxFail;
}
}
line1x = FindBestSolidLine(dec, reg, 0, 0, +1, DmtxUndefined);
if(line1x.mag < 5) {
TrailClear(dec, reg, 0x40);
return DmtxFail;
}
err = FindTravelLimits(dec, reg, &line1x);
if(line1x.distSq < 100 || line1x.devn * 10 >= sqrt((double)line1x.distSq)) {
TrailClear(dec, reg, 0x40);
return DmtxFail;
}
assert(line1x.stepPos >= line1x.stepNeg);
fTmp = FollowSeek(dec, reg, line1x.stepPos + 5);
line2p = FindBestSolidLine(dec, reg, fTmp.step, line1x.stepNeg, +1, line1x.angle);
fTmp = FollowSeek(dec, reg, line1x.stepNeg - 5);
line2n = FindBestSolidLine(dec, reg, fTmp.step, line1x.stepPos, -1, line1x.angle);
if(max(line2p.mag, line2n.mag) < 5)
return DmtxFail;
if(line2p.mag > line2n.mag) {
line2x = line2p;
err = FindTravelLimits(dec, reg, &line2x);
if(line2x.distSq < 100 || line2x.devn * 10 >= sqrt((double)line2x.distSq))
return DmtxFail;
cross = ((line1x.locPos.X - line1x.locNeg.X) * (line2x.locPos.Y - line2x.locNeg.Y)) -
((line1x.locPos.Y - line1x.locNeg.Y) * (line2x.locPos.X - line2x.locNeg.X));
if(cross > 0) {
/* Condition 2 */
reg->polarity = +1;
reg->locR = line2x.locPos;
reg->stepR = line2x.stepPos;
reg->locT = line1x.locNeg;
reg->stepT = line1x.stepNeg;
reg->leftLoc = line1x.locBeg;
reg->leftAngle = line1x.angle;
reg->bottomLoc = line2x.locBeg;
reg->bottomAngle = line2x.angle;
reg->leftLine = line1x;
reg->bottomLine = line2x;
}
else {
/* Condition 3 */
reg->polarity = -1;
reg->locR = line1x.locNeg;
reg->stepR = line1x.stepNeg;
reg->locT = line2x.locPos;
reg->stepT = line2x.stepPos;
reg->leftLoc = line2x.locBeg;
reg->leftAngle = line2x.angle;
reg->bottomLoc = line1x.locBeg;
reg->bottomAngle = line1x.angle;
reg->leftLine = line2x;
reg->bottomLine = line1x;
}
}
else {
line2x = line2n;
err = FindTravelLimits(dec, reg, &line2x);
if(line2x.distSq < 100 || line2x.devn / sqrt((double)line2x.distSq) >= 0.1)
return DmtxFail;
cross = ((line1x.locNeg.X - line1x.locPos.X) * (line2x.locNeg.Y - line2x.locPos.Y)) -
((line1x.locNeg.Y - line1x.locPos.Y) * (line2x.locNeg.X - line2x.locPos.X));
if(cross > 0) {
/* Condition 1 */
reg->polarity = -1;
reg->locR = line2x.locNeg;
reg->stepR = line2x.stepNeg;
reg->locT = line1x.locPos;
reg->stepT = line1x.stepPos;
reg->leftLoc = line1x.locBeg;
reg->leftAngle = line1x.angle;
reg->bottomLoc = line2x.locBeg;
reg->bottomAngle = line2x.angle;
reg->leftLine = line1x;
reg->bottomLine = line2x;
}
else {
/* Condition 4 */
reg->polarity = +1;
reg->locR = line1x.locPos;
reg->stepR = line1x.stepPos;
reg->locT = line2x.locNeg;
reg->stepT = line2x.stepNeg;
reg->leftLoc = line2x.locBeg;
reg->leftAngle = line2x.angle;
reg->bottomLoc = line1x.locBeg;
reg->bottomAngle = line1x.angle;
reg->leftLine = line2x;
reg->bottomLine = line1x;
}
}
/* CALLBACK_POINT_PLOT(reg->locR, 2, 1, 1);
CALLBACK_POINT_PLOT(reg->locT, 2, 1, 1); */
reg->leftKnown = reg->bottomKnown = 1;
return DmtxPass;
}
/**
*
*
*/
static long
DistanceSquared(DmtxPixelLoc a, DmtxPixelLoc b)
{
long xDelta, yDelta;
xDelta = a.X - b.X;
yDelta = a.Y - b.Y;
return (xDelta * xDelta) + (yDelta * yDelta);
}
/**
*
*
*/
extern DmtxPassFail
dmtxRegionUpdateCorners(DmtxDecode *dec, DmtxRegion *reg, DmtxVector2 p00,
DmtxVector2 p10, DmtxVector2 p11, DmtxVector2 p01)
{
double xMax, yMax;
double tx, ty, phi, shx, scx, scy, skx, sky;
double dimOT, dimOR, dimTX, dimRX, ratio;
DmtxVector2 vOT, vOR, vTX, vRX, vTmp;
DmtxMatrix3 m, mtxy, mphi, mshx, mscx, mscy, mscxy, msky, mskx;
xMax = (double)(dmtxDecodeGetProp(dec, DmtxPropWidth) - 1);
yMax = (double)(dmtxDecodeGetProp(dec, DmtxPropHeight) - 1);
if(p00.X < 0.0 || p00.Y < 0.0 || p00.X > xMax || p00.Y > yMax ||
p01.X < 0.0 || p01.Y < 0.0 || p01.X > xMax || p01.Y > yMax ||
p10.X < 0.0 || p10.Y < 0.0 || p10.X > xMax || p10.Y > yMax)
return DmtxFail;
dimOT = dmtxVector2Mag(dmtxVector2Sub(&vOT, &p01, &p00)); /* XXX could use MagSquared() */
dimOR = dmtxVector2Mag(dmtxVector2Sub(&vOR, &p10, &p00));
dimTX = dmtxVector2Mag(dmtxVector2Sub(&vTX, &p11, &p01));
dimRX = dmtxVector2Mag(dmtxVector2Sub(&vRX, &p11, &p10));
/* Verify that sides are reasonably long */
if(dimOT <= 8.0 || dimOR <= 8.0 || dimTX <= 8.0 || dimRX <= 8.0)
return DmtxFail;
/* Verify that the 4 corners define a reasonably fat quadrilateral */
ratio = dimOT / dimRX;
if(ratio <= 0.5 || ratio >= 2.0)
return DmtxFail;
ratio = dimOR / dimTX;
if(ratio <= 0.5 || ratio >= 2.0)
return DmtxFail;
/* Verify this is not a bowtie shape */
if(dmtxVector2Cross(&vOR, &vRX) <= 0.0 ||
dmtxVector2Cross(&vOT, &vTX) >= 0.0)
return DmtxFail;
if(RightAngleTrueness(p00, p10, p11, M_PI_2) <= dec->squareDevn)
return DmtxFail;
if(RightAngleTrueness(p10, p11, p01, M_PI_2) <= dec->squareDevn)
return DmtxFail;
/* Calculate values needed for transformations */
tx = -1 * p00.X;
ty = -1 * p00.Y;
dmtxMatrix3Translate(mtxy, tx, ty);
phi = atan2(vOT.X, vOT.Y);
dmtxMatrix3Rotate(mphi, phi);
dmtxMatrix3Multiply(m, mtxy, mphi);
dmtxMatrix3VMultiply(&vTmp, &p10, m);
shx = -vTmp.Y / vTmp.X;
dmtxMatrix3Shear(mshx, 0.0, shx);
dmtxMatrix3MultiplyBy(m, mshx);
scx = 1.0/vTmp.X;
dmtxMatrix3Scale(mscx, scx, 1.0);
dmtxMatrix3MultiplyBy(m, mscx);
dmtxMatrix3VMultiply(&vTmp, &p11, m);
scy = 1.0/vTmp.Y;
dmtxMatrix3Scale(mscy, 1.0, scy);
dmtxMatrix3MultiplyBy(m, mscy);
dmtxMatrix3VMultiply(&vTmp, &p11, m);
skx = vTmp.X;
dmtxMatrix3LineSkewSide(mskx, 1.0, skx, 1.0);
dmtxMatrix3MultiplyBy(m, mskx);
dmtxMatrix3VMultiply(&vTmp, &p01, m);
sky = vTmp.Y;
dmtxMatrix3LineSkewTop(msky, sky, 1.0, 1.0);
dmtxMatrix3Multiply(reg->raw2fit, m, msky);
/* Create inverse matrix by reverse (avoid straight matrix inversion) */
dmtxMatrix3LineSkewTopInv(msky, sky, 1.0, 1.0);
dmtxMatrix3LineSkewSideInv(mskx, 1.0, skx, 1.0);
dmtxMatrix3Multiply(m, msky, mskx);
dmtxMatrix3Scale(mscxy, 1.0/scx, 1.0/scy);
dmtxMatrix3MultiplyBy(m, mscxy);
dmtxMatrix3Shear(mshx, 0.0, -shx);
dmtxMatrix3MultiplyBy(m, mshx);
dmtxMatrix3Rotate(mphi, -phi);
dmtxMatrix3MultiplyBy(m, mphi);
dmtxMatrix3Translate(mtxy, -tx, -ty);
dmtxMatrix3Multiply(reg->fit2raw, m, mtxy);
return DmtxPass;
}
/**
*
*
*/
extern DmtxPassFail
dmtxRegionUpdateXfrms(DmtxDecode *dec, DmtxRegion *reg)
{
double radians;
DmtxRay2 rLeft, rBottom, rTop, rRight;
DmtxVector2 p00, p10, p11, p01;
assert(reg->leftKnown != 0 && reg->bottomKnown != 0);
/* Build ray representing left edge */
rLeft.p.X = (double)reg->leftLoc.X;
rLeft.p.Y = (double)reg->leftLoc.Y;
radians = reg->leftAngle * (M_PI/DMTX_HOUGH_RES);
rLeft.v.X = cos(radians);
rLeft.v.Y = sin(radians);
rLeft.tMin = 0.0;
rLeft.tMax = dmtxVector2Norm(&rLeft.v);
/* Build ray representing bottom edge */
rBottom.p.X = (double)reg->bottomLoc.X;
rBottom.p.Y = (double)reg->bottomLoc.Y;
radians = reg->bottomAngle * (M_PI/DMTX_HOUGH_RES);
rBottom.v.X = cos(radians);
rBottom.v.Y = sin(radians);
rBottom.tMin = 0.0;
rBottom.tMax = dmtxVector2Norm(&rBottom.v);
/* Build ray representing top edge */
if(reg->topKnown != 0) {
rTop.p.X = (double)reg->topLoc.X;
rTop.p.Y = (double)reg->topLoc.Y;
radians = reg->topAngle * (M_PI/DMTX_HOUGH_RES);
rTop.v.X = cos(radians);
rTop.v.Y = sin(radians);
rTop.tMin = 0.0;
rTop.tMax = dmtxVector2Norm(&rTop.v);
}
else {
rTop.p.X = (double)reg->locT.X;
rTop.p.Y = (double)reg->locT.Y;
radians = reg->bottomAngle * (M_PI/DMTX_HOUGH_RES);
rTop.v.X = cos(radians);
rTop.v.Y = sin(radians);
rTop.tMin = 0.0;
rTop.tMax = rBottom.tMax;
}
/* Build ray representing right edge */
if(reg->rightKnown != 0) {
rRight.p.X = (double)reg->rightLoc.X;
rRight.p.Y = (double)reg->rightLoc.Y;
radians = reg->rightAngle * (M_PI/DMTX_HOUGH_RES);
rRight.v.X = cos(radians);
rRight.v.Y = sin(radians);
rRight.tMin = 0.0;
rRight.tMax = dmtxVector2Norm(&rRight.v);
}
else {
rRight.p.X = (double)reg->locR.X;
rRight.p.Y = (double)reg->locR.Y;
radians = reg->leftAngle * (M_PI/DMTX_HOUGH_RES);
rRight.v.X = cos(radians);
rRight.v.Y = sin(radians);
rRight.tMin = 0.0;
rRight.tMax = rLeft.tMax;
}
/* Calculate 4 corners, real or imagined */
if(dmtxRay2Intersect(&p00, &rLeft, &rBottom) == DmtxFail)
return DmtxFail;
if(dmtxRay2Intersect(&p10, &rBottom, &rRight) == DmtxFail)
return DmtxFail;
if(dmtxRay2Intersect(&p11, &rRight, &rTop) == DmtxFail)
return DmtxFail;
if(dmtxRay2Intersect(&p01, &rTop, &rLeft) == DmtxFail)
return DmtxFail;
if(dmtxRegionUpdateCorners(dec, reg, p00, p10, p11, p01) != DmtxPass)
return DmtxFail;
return DmtxPass;
}
/**
*
*
*/
static double
RightAngleTrueness(DmtxVector2 c0, DmtxVector2 c1, DmtxVector2 c2, double angle)
{
DmtxVector2 vA, vB;
DmtxMatrix3 m;
dmtxVector2Norm(dmtxVector2Sub(&vA, &c0, &c1));
dmtxVector2Norm(dmtxVector2Sub(&vB, &c2, &c1));
dmtxMatrix3Rotate(m, angle);
dmtxMatrix3VMultiplyBy(&vB, m);
return dmtxVector2Dot(&vA, &vB);
}
/**
* \brief Read color of Data Matrix module location
* \param dec
* \param reg
* \param symbolRow
* \param symbolCol
* \param sizeIdx
* \return Averaged module color
*/
static int
ReadModuleColor(DmtxDecode *dec, DmtxRegion *reg, int symbolRow, int symbolCol,
int sizeIdx, int colorPlane)
{
int i;
int symbolRows, symbolCols;
int color, colorTmp;
double sampleX[] = { 0.5, 0.4, 0.5, 0.6, 0.5 };
double sampleY[] = { 0.5, 0.5, 0.4, 0.5, 0.6 };
DmtxVector2 p;
symbolRows = dmtxGetSymbolAttribute(DmtxSymAttribSymbolRows, sizeIdx);
symbolCols = dmtxGetSymbolAttribute(DmtxSymAttribSymbolCols, sizeIdx);
color = 0;
for(i = 0; i < 5; i++) {
p.X = (1.0/symbolCols) * (symbolCol + sampleX[i]);
p.Y = (1.0/symbolRows) * (symbolRow + sampleY[i]);
dmtxMatrix3VMultiplyBy(&p, reg->fit2raw);
//fprintf(stdout, "%dx%d\n", (int)(p.X + 0.5), (int)(p.Y + 0.5));
dmtxDecodeGetPixelValue(dec, (int)(p.X + 0.5), (int)(p.Y + 0.5),
colorPlane, &colorTmp);
color += colorTmp;
}
//fprintf(stdout, "\n");
return color/5;
}
/**
* \brief Determine barcode size, expressed in modules
* \param image
* \param reg
* \return DmtxPass | DmtxFail
*/
static DmtxPassFail
MatrixRegionFindSize(DmtxDecode *dec, DmtxRegion *reg)
{
int row, col;
int sizeIdxBeg, sizeIdxEnd;
int sizeIdx, bestSizeIdx;
int symbolRows, symbolCols;
int jumpCount, errors;
int color;
int colorOnAvg, bestColorOnAvg;
int colorOffAvg, bestColorOffAvg;
int contrast, bestContrast;
// DmtxImage *img;
// img = dec->image;
bestSizeIdx = DmtxUndefined;
bestContrast = 0;
bestColorOnAvg = bestColorOffAvg = 0;
if(dec->sizeIdxExpected == DmtxSymbolShapeAuto) {
sizeIdxBeg = 0;
sizeIdxEnd = DmtxSymbolSquareCount + DmtxSymbolRectCount;
}
else if(dec->sizeIdxExpected == DmtxSymbolSquareAuto) {
sizeIdxBeg = 0;
sizeIdxEnd = DmtxSymbolSquareCount;
}
else if(dec->sizeIdxExpected == DmtxSymbolRectAuto) {
sizeIdxBeg = DmtxSymbolSquareCount;
sizeIdxEnd = DmtxSymbolSquareCount + DmtxSymbolRectCount;
}
else {
sizeIdxBeg = dec->sizeIdxExpected;
sizeIdxEnd = dec->sizeIdxExpected + 1;
}
/* Test each barcode size to find best contrast in calibration modules */
for(sizeIdx = sizeIdxBeg; sizeIdx < sizeIdxEnd; sizeIdx++) {
symbolRows = dmtxGetSymbolAttribute(DmtxSymAttribSymbolRows, sizeIdx);
symbolCols = dmtxGetSymbolAttribute(DmtxSymAttribSymbolCols, sizeIdx);
colorOnAvg = colorOffAvg = 0;
/* Sum module colors along horizontal calibration bar */
row = symbolRows - 1;
for(col = 0; col < symbolCols; col++) {
color = ReadModuleColor(dec, reg, row, col, sizeIdx, reg->flowBegin.plane);
if((col & 0x01) != 0x00)
colorOffAvg += color;
else
colorOnAvg += color;
}
/* Sum module colors along vertical calibration bar */
col = symbolCols - 1;
for(row = 0; row < symbolRows; row++) {
color = ReadModuleColor(dec, reg, row, col, sizeIdx, reg->flowBegin.plane);
if((row & 0x01) != 0x00)
colorOffAvg += color;
else
colorOnAvg += color;
}
colorOnAvg = (colorOnAvg * 2)/(symbolRows + symbolCols);
colorOffAvg = (colorOffAvg * 2)/(symbolRows + symbolCols);
contrast = abs(colorOnAvg - colorOffAvg);
if(contrast < 20)
continue;
if(contrast > bestContrast) {
bestContrast = contrast;
bestSizeIdx = sizeIdx;
bestColorOnAvg = colorOnAvg;
bestColorOffAvg = colorOffAvg;
}
}
/* If no sizes produced acceptable contrast then call it quits */
if(bestSizeIdx == DmtxUndefined || bestContrast < 20)
return DmtxFail;
reg->sizeIdx = bestSizeIdx;
reg->onColor = bestColorOnAvg;
reg->offColor = bestColorOffAvg;
reg->symbolRows = dmtxGetSymbolAttribute(DmtxSymAttribSymbolRows, reg->sizeIdx);
reg->symbolCols = dmtxGetSymbolAttribute(DmtxSymAttribSymbolCols, reg->sizeIdx);
reg->mappingRows = dmtxGetSymbolAttribute(DmtxSymAttribMappingMatrixRows, reg->sizeIdx);
reg->mappingCols = dmtxGetSymbolAttribute(DmtxSymAttribMappingMatrixCols, reg->sizeIdx);
/* Tally jumps on horizontal calibration bar to verify sizeIdx */
jumpCount = CountJumpTally(dec, reg, 0, reg->symbolRows - 1, DmtxDirRight);
errors = abs(1 + jumpCount - reg->symbolCols);
if(jumpCount < 0 || errors > 2)
return DmtxFail;
/* Tally jumps on vertical calibration bar to verify sizeIdx */
jumpCount = CountJumpTally(dec, reg, reg->symbolCols - 1, 0, DmtxDirUp);
errors = abs(1 + jumpCount - reg->symbolRows);
if(jumpCount < 0 || errors > 2)
return DmtxFail;
/* Tally jumps on horizontal finder bar to verify sizeIdx */
errors = CountJumpTally(dec, reg, 0, 0, DmtxDirRight);
if(jumpCount < 0 || errors > 2)
return DmtxFail;
/* Tally jumps on vertical finder bar to verify sizeIdx */
errors = CountJumpTally(dec, reg, 0, 0, DmtxDirUp);
if(errors < 0 || errors > 2)
return DmtxFail;
/* Tally jumps on surrounding whitespace, else fail */
errors = CountJumpTally(dec, reg, 0, -1, DmtxDirRight);
if(errors < 0 || errors > 2)
return DmtxFail;
errors = CountJumpTally(dec, reg, -1, 0, DmtxDirUp);
if(errors < 0 || errors > 2)
return DmtxFail;
errors = CountJumpTally(dec, reg, 0, reg->symbolRows, DmtxDirRight);
if(errors < 0 || errors > 2)
return DmtxFail;
errors = CountJumpTally(dec, reg, reg->symbolCols, 0, DmtxDirUp);
if(errors < 0 || errors > 2)
return DmtxFail;
return DmtxPass;
}
/**
* \brief Count the number of number of transitions between light and dark
* \param img
* \param reg
* \param xStart
* \param yStart
* \param dir
* \return Jump count
*/
static int
CountJumpTally(DmtxDecode *dec, DmtxRegion *reg, int xStart, int yStart, DmtxDirection dir)
{
int x, xInc = 0;
int y, yInc = 0;
int state = DmtxModuleOn;
int jumpCount = 0;
int jumpThreshold;
int tModule, tPrev;
int darkOnLight;
int color;
assert(xStart == 0 || yStart == 0);
assert(dir == DmtxDirRight || dir == DmtxDirUp);
if(dir == DmtxDirRight)
xInc = 1;
else
yInc = 1;
if(xStart == -1 || xStart == reg->symbolCols ||
yStart == -1 || yStart == reg->symbolRows)
state = DmtxModuleOff;
darkOnLight = (int)(reg->offColor > reg->onColor);
jumpThreshold = abs((int)(0.4 * (reg->onColor - reg->offColor) + 0.5));
color = ReadModuleColor(dec, reg, yStart, xStart, reg->sizeIdx, reg->flowBegin.plane);
tModule = (darkOnLight) ? reg->offColor - color : color - reg->offColor;
for(x = xStart + xInc, y = yStart + yInc;
(dir == DmtxDirRight && x < reg->symbolCols) ||
(dir == DmtxDirUp && y < reg->symbolRows);
x += xInc, y += yInc) {
tPrev = tModule;
color = ReadModuleColor(dec, reg, y, x, reg->sizeIdx, reg->flowBegin.plane);
tModule = (darkOnLight) ? reg->offColor - color : color - reg->offColor;
if(state == DmtxModuleOff) {
if(tModule > tPrev + jumpThreshold) {
jumpCount++;
state = DmtxModuleOn;
}
}
else {
if(tModule < tPrev - jumpThreshold) {
jumpCount++;
state = DmtxModuleOff;
}
}
}
return jumpCount;
}
/**
*
*
*/
static DmtxPointFlow
GetPointFlow(DmtxDecode *dec, int colorPlane, DmtxPixelLoc loc, int arrive)
{
static const int coefficient[] = { 0, 1, 2, 1, 0, -1, -2, -1 };
int err;
int patternIdx, coefficientIdx;
int compass, compassMax;
int mag[4] = { 0 };
int xAdjust, yAdjust;
int color, colorPattern[8];
DmtxPointFlow flow;
for(patternIdx = 0; patternIdx < 8; patternIdx++) {
xAdjust = loc.X + dmtxPatternX[patternIdx];
yAdjust = loc.Y + dmtxPatternY[patternIdx];
err = dmtxDecodeGetPixelValue(dec, xAdjust, yAdjust, colorPlane,
&colorPattern[patternIdx]);
if(err == DmtxFail)
return dmtxBlankEdge;
}
/* Calculate this pixel's flow intensity for each direction (-45, 0, 45, 90) */
compassMax = 0;
for(compass = 0; compass < 4; compass++) {
/* Add portion from each position in the convolution matrix pattern */
for(patternIdx = 0; patternIdx < 8; patternIdx++) {
coefficientIdx = (patternIdx - compass + 8) % 8;
if(coefficient[coefficientIdx] == 0)
continue;
color = colorPattern[patternIdx];
switch(coefficient[coefficientIdx]) {
case 2:
mag[compass] += color;
/* Fall through */
case 1:
mag[compass] += color;
break;
case -2:
mag[compass] -= color;
/* Fall through */
case -1:
mag[compass] -= color;
break;
}
}
/* Identify strongest compass flow */
if(compass != 0 && abs(mag[compass]) > abs(mag[compassMax]))
compassMax = compass;
}
/* Convert signed compass direction into unique flow directions (0-7) */
flow.plane = colorPlane;
flow.arrive = arrive;
flow.depart = (mag[compassMax] > 0) ? compassMax + 4 : compassMax;
flow.mag = abs(mag[compassMax]);
flow.loc = loc;
return flow;
}
/**
*
*
*/
static DmtxPointFlow
FindStrongestNeighbor(DmtxDecode *dec, DmtxPointFlow center, int sign)
{
int i;
int strongIdx;
int attempt, attemptDiff;
int occupied;
unsigned char *cache;
DmtxPixelLoc loc;
DmtxPointFlow flow[8];
attempt = (sign < 0) ? center.depart : (center.depart+4)%8;
occupied = 0;
strongIdx = DmtxUndefined;
for(i = 0; i < 8; i++) {
loc.X = center.loc.X + dmtxPatternX[i];
loc.Y = center.loc.Y + dmtxPatternY[i];
cache = dmtxDecodeGetCache(dec, loc.X, loc.Y);
if(cache == NULL)
continue;
if((int)(*cache & 0x80) != 0x00) {
if(++occupied > 2)
return dmtxBlankEdge;
else
continue;
}
attemptDiff = abs(attempt - i);
if(attemptDiff > 4)
attemptDiff = 8 - attemptDiff;
if(attemptDiff > 1)
continue;
flow[i] = GetPointFlow(dec, center.plane, loc, i);
if(strongIdx == DmtxUndefined || flow[i].mag > flow[strongIdx].mag ||
(flow[i].mag == flow[strongIdx].mag && ((i & 0x01) != 0))) {
strongIdx = i;
}
}
return (strongIdx == DmtxUndefined) ? dmtxBlankEdge : flow[strongIdx];
}
/**
*
*
*/
static DmtxFollow
FollowSeek(DmtxDecode *dec, DmtxRegion *reg, int seek)
{
int i;
int sign;
DmtxFollow follow;
follow.loc = reg->flowBegin.loc;
follow.step = 0;
follow.ptr = dmtxDecodeGetCache(dec, follow.loc.X, follow.loc.Y);
assert(follow.ptr != NULL);
follow.neighbor = *follow.ptr;
sign = (seek > 0) ? +1 : -1;
for(i = 0; i != seek; i += sign) {
follow = FollowStep(dec, reg, follow, sign);
assert(follow.ptr != NULL);
assert(abs(follow.step) <= reg->stepsTotal);
}
return follow;
}
/**
*
*
*/
static DmtxFollow
FollowSeekLoc(DmtxDecode *dec, DmtxPixelLoc loc)
{
DmtxFollow follow;
follow.loc = loc;
follow.step = 0;
follow.ptr = dmtxDecodeGetCache(dec, follow.loc.X, follow.loc.Y);
assert(follow.ptr != NULL);
follow.neighbor = *follow.ptr;
return follow;
}
/**
*
*
*/
static DmtxFollow
FollowStep(DmtxDecode *dec, DmtxRegion *reg, DmtxFollow followBeg, int sign)
{