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41 #include "_cv.h"
42 #include <float.h>
43 #include <stdio.h>
44 
45 static void
intersect(CvPoint2D32f pt,CvSize win_size,CvSize imgSize,CvPoint * min_pt,CvPoint * max_pt)46 intersect( CvPoint2D32f pt, CvSize win_size, CvSize imgSize,
47            CvPoint* min_pt, CvPoint* max_pt )
48 {
49     CvPoint ipt;
50 
51     ipt.x = cvFloor( pt.x );
52     ipt.y = cvFloor( pt.y );
53 
54     ipt.x -= win_size.width;
55     ipt.y -= win_size.height;
56 
57     win_size.width = win_size.width * 2 + 1;
58     win_size.height = win_size.height * 2 + 1;
59 
60     min_pt->x = MAX( 0, -ipt.x );
61     min_pt->y = MAX( 0, -ipt.y );
62     max_pt->x = MIN( win_size.width, imgSize.width - ipt.x );
63     max_pt->y = MIN( win_size.height, imgSize.height - ipt.y );
64 }
65 
66 
icvMinimalPyramidSize(CvSize imgSize)67 static int icvMinimalPyramidSize( CvSize imgSize )
68 {
69     return cvAlign(imgSize.width,8) * imgSize.height / 3;
70 }
71 
72 
73 static void
icvInitPyramidalAlgorithm(const CvMat * imgA,const CvMat * imgB,CvMat * pyrA,CvMat * pyrB,int level,CvTermCriteria * criteria,int max_iters,int flags,uchar *** imgI,uchar *** imgJ,int ** step,CvSize ** size,double ** scale,uchar ** buffer)74 icvInitPyramidalAlgorithm( const CvMat* imgA, const CvMat* imgB,
75                            CvMat* pyrA, CvMat* pyrB,
76                            int level, CvTermCriteria * criteria,
77                            int max_iters, int flags,
78                            uchar *** imgI, uchar *** imgJ,
79                            int **step, CvSize** size,
80                            double **scale, uchar ** buffer )
81 {
82     CV_FUNCNAME( "icvInitPyramidalAlgorithm" );
83 
84     __BEGIN__;
85 
86     const int ALIGN = 8;
87     int pyrBytes, bufferBytes = 0, elem_size;
88     int level1 = level + 1;
89 
90     int i;
91     CvSize imgSize, levelSize;
92 
93     *buffer = 0;
94     *imgI = *imgJ = 0;
95     *step = 0;
96     *scale = 0;
97     *size = 0;
98 
99     /* check input arguments */
100     if( ((flags & CV_LKFLOW_PYR_A_READY) != 0 && !pyrA) ||
101         ((flags & CV_LKFLOW_PYR_B_READY) != 0 && !pyrB) )
102         CV_ERROR( CV_StsNullPtr, "Some of the precomputed pyramids are missing" );
103 
104     if( level < 0 )
105         CV_ERROR( CV_StsOutOfRange, "The number of pyramid layers is negative" );
106 
107     switch( criteria->type )
108     {
109     case CV_TERMCRIT_ITER:
110         criteria->epsilon = 0.f;
111         break;
112     case CV_TERMCRIT_EPS:
113         criteria->max_iter = max_iters;
114         break;
115     case CV_TERMCRIT_ITER | CV_TERMCRIT_EPS:
116         break;
117     default:
118         assert( 0 );
119         CV_ERROR( CV_StsBadArg, "Invalid termination criteria" );
120     }
121 
122     /* compare squared values */
123     criteria->epsilon *= criteria->epsilon;
124 
125     /* set pointers and step for every level */
126     pyrBytes = 0;
127 
128     imgSize = cvGetSize(imgA);
129     elem_size = CV_ELEM_SIZE(imgA->type);
130     levelSize = imgSize;
131 
132     for( i = 1; i < level1; i++ )
133     {
134         levelSize.width = (levelSize.width + 1) >> 1;
135         levelSize.height = (levelSize.height + 1) >> 1;
136 
137         int tstep = cvAlign(levelSize.width,ALIGN) * elem_size;
138         pyrBytes += tstep * levelSize.height;
139     }
140 
141     assert( pyrBytes <= imgSize.width * imgSize.height * elem_size * 4 / 3 );
142 
143     /* buffer_size = <size for patches> + <size for pyramids> */
144     bufferBytes = (int)((level1 >= 0) * ((pyrA->data.ptr == 0) +
145         (pyrB->data.ptr == 0)) * pyrBytes +
146         (sizeof(imgI[0][0]) * 2 + sizeof(step[0][0]) +
147          sizeof(size[0][0]) + sizeof(scale[0][0])) * level1);
148 
149     CV_CALL( *buffer = (uchar *)cvAlloc( bufferBytes ));
150 
151     *imgI = (uchar **) buffer[0];
152     *imgJ = *imgI + level1;
153     *step = (int *) (*imgJ + level1);
154     *scale = (double *) (*step + level1);
155     *size = (CvSize *)(*scale + level1);
156 
157     imgI[0][0] = imgA->data.ptr;
158     imgJ[0][0] = imgB->data.ptr;
159     step[0][0] = imgA->step;
160     scale[0][0] = 1;
161     size[0][0] = imgSize;
162 
163     if( level > 0 )
164     {
165         uchar *bufPtr = (uchar *) (*size + level1);
166         uchar *ptrA = pyrA->data.ptr;
167         uchar *ptrB = pyrB->data.ptr;
168 
169         if( !ptrA )
170         {
171             ptrA = bufPtr;
172             bufPtr += pyrBytes;
173         }
174 
175         if( !ptrB )
176             ptrB = bufPtr;
177 
178         levelSize = imgSize;
179 
180         /* build pyramids for both frames */
181         for( i = 1; i <= level; i++ )
182         {
183             int levelBytes;
184             CvMat prev_level, next_level;
185 
186             levelSize.width = (levelSize.width + 1) >> 1;
187             levelSize.height = (levelSize.height + 1) >> 1;
188 
189             size[0][i] = levelSize;
190             step[0][i] = cvAlign( levelSize.width, ALIGN ) * elem_size;
191             scale[0][i] = scale[0][i - 1] * 0.5;
192 
193             levelBytes = step[0][i] * levelSize.height;
194             imgI[0][i] = (uchar *) ptrA;
195             ptrA += levelBytes;
196 
197             if( !(flags & CV_LKFLOW_PYR_A_READY) )
198             {
199                 prev_level = cvMat( size[0][i-1].height, size[0][i-1].width, CV_8UC1 );
200                 next_level = cvMat( size[0][i].height, size[0][i].width, CV_8UC1 );
201                 cvSetData( &prev_level, imgI[0][i-1], step[0][i-1] );
202                 cvSetData( &next_level, imgI[0][i], step[0][i] );
203                 cvPyrDown( &prev_level, &next_level );
204             }
205 
206             imgJ[0][i] = (uchar *) ptrB;
207             ptrB += levelBytes;
208 
209             if( !(flags & CV_LKFLOW_PYR_B_READY) )
210             {
211                 prev_level = cvMat( size[0][i-1].height, size[0][i-1].width, CV_8UC1 );
212                 next_level = cvMat( size[0][i].height, size[0][i].width, CV_8UC1 );
213                 cvSetData( &prev_level, imgJ[0][i-1], step[0][i-1] );
214                 cvSetData( &next_level, imgJ[0][i], step[0][i] );
215                 cvPyrDown( &prev_level, &next_level );
216             }
217         }
218     }
219 
220     __END__;
221 }
222 
223 
224 /* compute dI/dx and dI/dy */
225 static void
icvCalcIxIy_32f(const float * src,int src_step,float * dstX,float * dstY,int dst_step,CvSize src_size,const float * smooth_k,float * buffer0)226 icvCalcIxIy_32f( const float* src, int src_step, float* dstX, float* dstY, int dst_step,
227                  CvSize src_size, const float* smooth_k, float* buffer0 )
228 {
229     int src_width = src_size.width, dst_width = src_size.width-2;
230     int x, height = src_size.height - 2;
231     float* buffer1 = buffer0 + src_width;
232 
233     src_step /= sizeof(src[0]);
234     dst_step /= sizeof(dstX[0]);
235 
236     for( ; height--; src += src_step, dstX += dst_step, dstY += dst_step )
237     {
238         const float* src2 = src + src_step;
239         const float* src3 = src + src_step*2;
240 
241         for( x = 0; x < src_width; x++ )
242         {
243             float t0 = (src3[x] + src[x])*smooth_k[0] + src2[x]*smooth_k[1];
244             float t1 = src3[x] - src[x];
245             buffer0[x] = t0; buffer1[x] = t1;
246         }
247 
248         for( x = 0; x < dst_width; x++ )
249         {
250             float t0 = buffer0[x+2] - buffer0[x];
251             float t1 = (buffer1[x] + buffer1[x+2])*smooth_k[0] + buffer1[x+1]*smooth_k[1];
252             dstX[x] = t0; dstY[x] = t1;
253         }
254     }
255 }
256 
257 
258 icvOpticalFlowPyrLKInitAlloc_8u_C1R_t icvOpticalFlowPyrLKInitAlloc_8u_C1R_p = 0;
259 icvOpticalFlowPyrLKFree_8u_C1R_t icvOpticalFlowPyrLKFree_8u_C1R_p = 0;
260 icvOpticalFlowPyrLK_8u_C1R_t icvOpticalFlowPyrLK_8u_C1R_p = 0;
261 
262 
263 CV_IMPL void
cvCalcOpticalFlowPyrLK(const void * arrA,const void * arrB,void * pyrarrA,void * pyrarrB,const CvPoint2D32f * featuresA,CvPoint2D32f * featuresB,int count,CvSize winSize,int level,char * status,float * error,CvTermCriteria criteria,int flags)264 cvCalcOpticalFlowPyrLK( const void* arrA, const void* arrB,
265                         void* pyrarrA, void* pyrarrB,
266                         const CvPoint2D32f * featuresA,
267                         CvPoint2D32f * featuresB,
268                         int count, CvSize winSize, int level,
269                         char *status, float *error,
270                         CvTermCriteria criteria, int flags )
271 {
272     uchar *pyrBuffer = 0;
273     uchar *buffer = 0;
274     float* _error = 0;
275     char* _status = 0;
276 
277     void* ipp_optflow_state = 0;
278 
279     CV_FUNCNAME( "cvCalcOpticalFlowPyrLK" );
280 
281     __BEGIN__;
282 
283     const int MAX_ITERS = 100;
284 
285     CvMat stubA, *imgA = (CvMat*)arrA;
286     CvMat stubB, *imgB = (CvMat*)arrB;
287     CvMat pstubA, *pyrA = (CvMat*)pyrarrA;
288     CvMat pstubB, *pyrB = (CvMat*)pyrarrB;
289     CvSize imgSize;
290     static const float smoothKernel[] = { 0.09375, 0.3125, 0.09375 };  /* 3/32, 10/32, 3/32 */
291 
292     int bufferBytes = 0;
293     uchar **imgI = 0;
294     uchar **imgJ = 0;
295     int *step = 0;
296     double *scale = 0;
297     CvSize* size = 0;
298 
299     int threadCount = cvGetNumThreads();
300     float* _patchI[CV_MAX_THREADS];
301     float* _patchJ[CV_MAX_THREADS];
302     float* _Ix[CV_MAX_THREADS];
303     float* _Iy[CV_MAX_THREADS];
304 
305     int i, l;
306 
307     CvSize patchSize = cvSize( winSize.width * 2 + 1, winSize.height * 2 + 1 );
308     int patchLen = patchSize.width * patchSize.height;
309     int srcPatchLen = (patchSize.width + 2)*(patchSize.height + 2);
310 
311     CV_CALL( imgA = cvGetMat( imgA, &stubA ));
312     CV_CALL( imgB = cvGetMat( imgB, &stubB ));
313 
314     if( CV_MAT_TYPE( imgA->type ) != CV_8UC1 )
315         CV_ERROR( CV_StsUnsupportedFormat, "" );
316 
317     if( !CV_ARE_TYPES_EQ( imgA, imgB ))
318         CV_ERROR( CV_StsUnmatchedFormats, "" );
319 
320     if( !CV_ARE_SIZES_EQ( imgA, imgB ))
321         CV_ERROR( CV_StsUnmatchedSizes, "" );
322 
323     if( imgA->step != imgB->step )
324         CV_ERROR( CV_StsUnmatchedSizes, "imgA and imgB must have equal steps" );
325 
326     imgSize = cvGetMatSize( imgA );
327 
328     if( pyrA )
329     {
330         CV_CALL( pyrA = cvGetMat( pyrA, &pstubA ));
331 
332         if( pyrA->step*pyrA->height < icvMinimalPyramidSize( imgSize ) )
333             CV_ERROR( CV_StsBadArg, "pyramid A has insufficient size" );
334     }
335     else
336     {
337         pyrA = &pstubA;
338         pyrA->data.ptr = 0;
339     }
340 
341     if( pyrB )
342     {
343         CV_CALL( pyrB = cvGetMat( pyrB, &pstubB ));
344 
345         if( pyrB->step*pyrB->height < icvMinimalPyramidSize( imgSize ) )
346             CV_ERROR( CV_StsBadArg, "pyramid B has insufficient size" );
347     }
348     else
349     {
350         pyrB = &pstubB;
351         pyrB->data.ptr = 0;
352     }
353 
354     if( count == 0 )
355         EXIT;
356 
357     if( !featuresA || !featuresB )
358         CV_ERROR( CV_StsNullPtr, "Some of arrays of point coordinates are missing" );
359 
360     if( count < 0 )
361         CV_ERROR( CV_StsOutOfRange, "The number of tracked points is negative or zero" );
362 
363     if( winSize.width <= 1 || winSize.height <= 1 )
364         CV_ERROR( CV_StsBadSize, "Invalid search window size" );
365 
366     for( i = 0; i < threadCount; i++ )
367         _patchI[i] = _patchJ[i] = _Ix[i] = _Iy[i] = 0;
368 
369     CV_CALL( icvInitPyramidalAlgorithm( imgA, imgB, pyrA, pyrB,
370         level, &criteria, MAX_ITERS, flags,
371         &imgI, &imgJ, &step, &size, &scale, &pyrBuffer ));
372 
373     if( !status )
374         CV_CALL( status = _status = (char*)cvAlloc( count*sizeof(_status[0]) ));
375 
376 #if 0
377     if( icvOpticalFlowPyrLKInitAlloc_8u_C1R_p &&
378         icvOpticalFlowPyrLKFree_8u_C1R_p &&
379         icvOpticalFlowPyrLK_8u_C1R_p &&
380         winSize.width == winSize.height &&
381         icvOpticalFlowPyrLKInitAlloc_8u_C1R_p( &ipp_optflow_state, imgSize,
382                                                winSize.width*2+1, cvAlgHintAccurate ) >= 0 )
383     {
384         CvPyramid ipp_pyrA, ipp_pyrB;
385         static const double rate[] = { 1, 0.5, 0.25, 0.125, 0.0625, 0.03125, 0.015625, 0.0078125,
386                                        0.00390625, 0.001953125, 0.0009765625, 0.00048828125, 0.000244140625,
387                                        0.0001220703125 };
388         // initialize pyramid structures
389         assert( level < 14 );
390         ipp_pyrA.ptr = imgI;
391         ipp_pyrB.ptr = imgJ;
392         ipp_pyrA.sz = ipp_pyrB.sz = size;
393         ipp_pyrA.rate = ipp_pyrB.rate = (double*)rate;
394         ipp_pyrA.step = ipp_pyrB.step = step;
395         ipp_pyrA.state = ipp_pyrB.state = 0;
396         ipp_pyrA.level = ipp_pyrB.level = level;
397 
398         if( !error )
399             CV_CALL( error = _error = (float*)cvAlloc( count*sizeof(_error[0]) ));
400 
401         for( i = 0; i < count; i++ )
402             featuresB[i] = featuresA[i];
403 
404         if( icvOpticalFlowPyrLK_8u_C1R_p( &ipp_pyrA, &ipp_pyrB,
405             (const float*)featuresA, (float*)featuresB, status, error, count,
406             winSize.width*2 + 1, level, criteria.max_iter,
407             (float)criteria.epsilon, ipp_optflow_state ) >= 0 )
408         {
409             for( i = 0; i < count; i++ )
410                 status[i] = status[i] == 0;
411             EXIT;
412         }
413     }
414 #endif
415 
416     /* buffer_size = <size for patches> + <size for pyramids> */
417     bufferBytes = (srcPatchLen + patchLen * 3) * sizeof( _patchI[0][0] ) * threadCount;
418     CV_CALL( buffer = (uchar*)cvAlloc( bufferBytes ));
419 
420     for( i = 0; i < threadCount; i++ )
421     {
422         _patchI[i] = i == 0 ? (float*)buffer : _Iy[i-1] + patchLen;
423         _patchJ[i] = _patchI[i] + srcPatchLen;
424         _Ix[i] = _patchJ[i] + patchLen;
425         _Iy[i] = _Ix[i] + patchLen;
426     }
427 
428     memset( status, 1, count );
429     if( error )
430         memset( error, 0, count*sizeof(error[0]) );
431 
432     if( !(flags & CV_LKFLOW_INITIAL_GUESSES) )
433         memcpy( featuresB, featuresA, count*sizeof(featuresA[0]));
434 
435     /* do processing from top pyramid level (smallest image)
436        to the bottom (original image) */
437     for( l = level; l >= 0; l-- )
438     {
439         CvSize levelSize = size[l];
440         int levelStep = step[l];
441 
442         {
443 #ifdef _OPENMP
444         #pragma omp parallel for num_threads(threadCount) schedule(dynamic)
445 #endif // _OPENMP
446         /* find flow for each given point */
447         for( i = 0; i < count; i++ )
448         {
449             CvPoint2D32f v;
450             CvPoint minI, maxI, minJ, maxJ;
451             CvSize isz, jsz;
452             int pt_status;
453             CvPoint2D32f u;
454             CvPoint prev_minJ = { -1, -1 }, prev_maxJ = { -1, -1 };
455             double Gxx = 0, Gxy = 0, Gyy = 0, D = 0, minEig = 0;
456             float prev_mx = 0, prev_my = 0;
457             int j, x, y;
458             int threadIdx = cvGetThreadNum();
459             float* patchI = _patchI[threadIdx];
460             float* patchJ = _patchJ[threadIdx];
461             float* Ix = _Ix[threadIdx];
462             float* Iy = _Iy[threadIdx];
463 
464             v.x = featuresB[i].x;
465             v.y = featuresB[i].y;
466             if( l < level )
467             {
468                 v.x += v.x;
469                 v.y += v.y;
470             }
471             else
472             {
473                 v.x = (float)(v.x * scale[l]);
474                 v.y = (float)(v.y * scale[l]);
475             }
476 
477             pt_status = status[i];
478             if( !pt_status )
479                 continue;
480 
481             minI = maxI = minJ = maxJ = cvPoint( 0, 0 );
482 
483             u.x = (float) (featuresA[i].x * scale[l]);
484             u.y = (float) (featuresA[i].y * scale[l]);
485 
486             intersect( u, winSize, levelSize, &minI, &maxI );
487             isz = jsz = cvSize(maxI.x - minI.x + 2, maxI.y - minI.y + 2);
488             u.x += (minI.x - (patchSize.width - maxI.x + 1))*0.5f;
489             u.y += (minI.y - (patchSize.height - maxI.y + 1))*0.5f;
490 
491             if( isz.width < 3 || isz.height < 3 ||
492                 icvGetRectSubPix_8u32f_C1R( imgI[l], levelStep, levelSize,
493                     patchI, isz.width*sizeof(patchI[0]), isz, u ) < 0 )
494             {
495                 /* point is outside the image. take the next */
496                 status[i] = 0;
497                 continue;
498             }
499 
500             icvCalcIxIy_32f( patchI, isz.width*sizeof(patchI[0]), Ix, Iy,
501                 (isz.width-2)*sizeof(patchI[0]), isz, smoothKernel, patchJ );
502 
503             for( j = 0; j < criteria.max_iter; j++ )
504             {
505                 double bx = 0, by = 0;
506                 float mx, my;
507                 CvPoint2D32f _v;
508 
509                 intersect( v, winSize, levelSize, &minJ, &maxJ );
510 
511                 minJ.x = MAX( minJ.x, minI.x );
512                 minJ.y = MAX( minJ.y, minI.y );
513 
514                 maxJ.x = MIN( maxJ.x, maxI.x );
515                 maxJ.y = MIN( maxJ.y, maxI.y );
516 
517                 jsz = cvSize(maxJ.x - minJ.x, maxJ.y - minJ.y);
518 
519                 _v.x = v.x + (minJ.x - (patchSize.width - maxJ.x + 1))*0.5f;
520                 _v.y = v.y + (minJ.y - (patchSize.height - maxJ.y + 1))*0.5f;
521 
522                 if( jsz.width < 1 || jsz.height < 1 ||
523                     icvGetRectSubPix_8u32f_C1R( imgJ[l], levelStep, levelSize, patchJ,
524                                                 jsz.width*sizeof(patchJ[0]), jsz, _v ) < 0 )
525                 {
526                     /* point is outside image. take the next */
527                     pt_status = 0;
528                     break;
529                 }
530 
531                 if( maxJ.x == prev_maxJ.x && maxJ.y == prev_maxJ.y &&
532                     minJ.x == prev_minJ.x && minJ.y == prev_minJ.y )
533                 {
534                     for( y = 0; y < jsz.height; y++ )
535                     {
536                         const float* pi = patchI +
537                             (y + minJ.y - minI.y + 1)*isz.width + minJ.x - minI.x + 1;
538                         const float* pj = patchJ + y*jsz.width;
539                         const float* ix = Ix +
540                             (y + minJ.y - minI.y)*(isz.width-2) + minJ.x - minI.x;
541                         const float* iy = Iy + (ix - Ix);
542 
543                         for( x = 0; x < jsz.width; x++ )
544                         {
545                             double t0 = pi[x] - pj[x];
546                             bx += t0 * ix[x];
547                             by += t0 * iy[x];
548                         }
549                     }
550                 }
551                 else
552                 {
553                     Gxx = Gyy = Gxy = 0;
554                     for( y = 0; y < jsz.height; y++ )
555                     {
556                         const float* pi = patchI +
557                             (y + minJ.y - minI.y + 1)*isz.width + minJ.x - minI.x + 1;
558                         const float* pj = patchJ + y*jsz.width;
559                         const float* ix = Ix +
560                             (y + minJ.y - minI.y)*(isz.width-2) + minJ.x - minI.x;
561                         const float* iy = Iy + (ix - Ix);
562 
563                         for( x = 0; x < jsz.width; x++ )
564                         {
565                             double t = pi[x] - pj[x];
566                             bx += (double) (t * ix[x]);
567                             by += (double) (t * iy[x]);
568                             Gxx += ix[x] * ix[x];
569                             Gxy += ix[x] * iy[x];
570                             Gyy += iy[x] * iy[x];
571                         }
572                     }
573 
574                     D = Gxx * Gyy - Gxy * Gxy;
575                     if( D < DBL_EPSILON )
576                     {
577                         pt_status = 0;
578                         break;
579                     }
580 
581                     // Adi Shavit - 2008.05
582                     if( flags & CV_LKFLOW_GET_MIN_EIGENVALS )
583                         minEig = (Gyy + Gxx - sqrt((Gxx-Gyy)*(Gxx-Gyy) + 4.*Gxy*Gxy))/(2*jsz.height*jsz.width);
584 
585                     D = 1. / D;
586 
587                     prev_minJ = minJ;
588                     prev_maxJ = maxJ;
589                 }
590 
591                 mx = (float) ((Gyy * bx - Gxy * by) * D);
592                 my = (float) ((Gxx * by - Gxy * bx) * D);
593 
594                 v.x += mx;
595                 v.y += my;
596 
597                 if( mx * mx + my * my < criteria.epsilon )
598                     break;
599 
600                 if( j > 0 && fabs(mx + prev_mx) < 0.01 && fabs(my + prev_my) < 0.01 )
601                 {
602                     v.x -= mx*0.5f;
603                     v.y -= my*0.5f;
604                     break;
605                 }
606                 prev_mx = mx;
607                 prev_my = my;
608             }
609 
610             featuresB[i] = v;
611             status[i] = (char)pt_status;
612             if( l == 0 && error && pt_status )
613             {
614                 /* calc error */
615                 double err = 0;
616                 if( flags & CV_LKFLOW_GET_MIN_EIGENVALS )
617                     err = minEig;
618                 else
619                 {
620                     for( y = 0; y < jsz.height; y++ )
621                     {
622                         const float* pi = patchI +
623                             (y + minJ.y - minI.y + 1)*isz.width + minJ.x - minI.x + 1;
624                         const float* pj = patchJ + y*jsz.width;
625 
626                         for( x = 0; x < jsz.width; x++ )
627                         {
628                             double t = pi[x] - pj[x];
629                             err += t * t;
630                         }
631                     }
632                     err = sqrt(err);
633                 }
634                 error[i] = (float)err;
635             }
636         } // end of point processing loop (i)
637         }
638     } // end of pyramid levels loop (l)
639 
640     __END__;
641 
642     if( ipp_optflow_state )
643         icvOpticalFlowPyrLKFree_8u_C1R_p( ipp_optflow_state );
644 
645     cvFree( &pyrBuffer );
646     cvFree( &buffer );
647     cvFree( &_error );
648     cvFree( &_status );
649 }
650 
651 
652 /* Affine tracking algorithm */
653 
654 CV_IMPL void
cvCalcAffineFlowPyrLK(const void * arrA,const void * arrB,void * pyrarrA,void * pyrarrB,const CvPoint2D32f * featuresA,CvPoint2D32f * featuresB,float * matrices,int count,CvSize winSize,int level,char * status,float * error,CvTermCriteria criteria,int flags)655 cvCalcAffineFlowPyrLK( const void* arrA, const void* arrB,
656                        void* pyrarrA, void* pyrarrB,
657                        const CvPoint2D32f * featuresA,
658                        CvPoint2D32f * featuresB,
659                        float *matrices, int count,
660                        CvSize winSize, int level,
661                        char *status, float *error,
662                        CvTermCriteria criteria, int flags )
663 {
664     const int MAX_ITERS = 100;
665 
666     char* _status = 0;
667     uchar *buffer = 0;
668     uchar *pyr_buffer = 0;
669 
670     CV_FUNCNAME( "cvCalcAffineFlowPyrLK" );
671 
672     __BEGIN__;
673 
674     CvMat stubA, *imgA = (CvMat*)arrA;
675     CvMat stubB, *imgB = (CvMat*)arrB;
676     CvMat pstubA, *pyrA = (CvMat*)pyrarrA;
677     CvMat pstubB, *pyrB = (CvMat*)pyrarrB;
678 
679     static const float smoothKernel[] = { 0.09375, 0.3125, 0.09375 };  /* 3/32, 10/32, 3/32 */
680 
681     int bufferBytes = 0;
682 
683     uchar **imgI = 0;
684     uchar **imgJ = 0;
685     int *step = 0;
686     double *scale = 0;
687     CvSize* size = 0;
688 
689     float *patchI;
690     float *patchJ;
691     float *Ix;
692     float *Iy;
693 
694     int i, j, k, l;
695 
696     CvSize patchSize = cvSize( winSize.width * 2 + 1, winSize.height * 2 + 1 );
697     int patchLen = patchSize.width * patchSize.height;
698     int patchStep = patchSize.width * sizeof( patchI[0] );
699 
700     CvSize srcPatchSize = cvSize( patchSize.width + 2, patchSize.height + 2 );
701     int srcPatchLen = srcPatchSize.width * srcPatchSize.height;
702     int srcPatchStep = srcPatchSize.width * sizeof( patchI[0] );
703     CvSize imgSize;
704     float eps = (float)MIN(winSize.width, winSize.height);
705 
706     CV_CALL( imgA = cvGetMat( imgA, &stubA ));
707     CV_CALL( imgB = cvGetMat( imgB, &stubB ));
708 
709     if( CV_MAT_TYPE( imgA->type ) != CV_8UC1 )
710         CV_ERROR( CV_StsUnsupportedFormat, "" );
711 
712     if( !CV_ARE_TYPES_EQ( imgA, imgB ))
713         CV_ERROR( CV_StsUnmatchedFormats, "" );
714 
715     if( !CV_ARE_SIZES_EQ( imgA, imgB ))
716         CV_ERROR( CV_StsUnmatchedSizes, "" );
717 
718     if( imgA->step != imgB->step )
719         CV_ERROR( CV_StsUnmatchedSizes, "imgA and imgB must have equal steps" );
720 
721     if( !matrices )
722         CV_ERROR( CV_StsNullPtr, "" );
723 
724     imgSize = cvGetMatSize( imgA );
725 
726     if( pyrA )
727     {
728         CV_CALL( pyrA = cvGetMat( pyrA, &pstubA ));
729 
730         if( pyrA->step*pyrA->height < icvMinimalPyramidSize( imgSize ) )
731             CV_ERROR( CV_StsBadArg, "pyramid A has insufficient size" );
732     }
733     else
734     {
735         pyrA = &pstubA;
736         pyrA->data.ptr = 0;
737     }
738 
739     if( pyrB )
740     {
741         CV_CALL( pyrB = cvGetMat( pyrB, &pstubB ));
742 
743         if( pyrB->step*pyrB->height < icvMinimalPyramidSize( imgSize ) )
744             CV_ERROR( CV_StsBadArg, "pyramid B has insufficient size" );
745     }
746     else
747     {
748         pyrB = &pstubB;
749         pyrB->data.ptr = 0;
750     }
751 
752     if( count == 0 )
753         EXIT;
754 
755     /* check input arguments */
756     if( !featuresA || !featuresB || !matrices )
757         CV_ERROR( CV_StsNullPtr, "" );
758 
759     if( winSize.width <= 1 || winSize.height <= 1 )
760         CV_ERROR( CV_StsOutOfRange, "the search window is too small" );
761 
762     if( count < 0 )
763         CV_ERROR( CV_StsOutOfRange, "" );
764 
765     CV_CALL( icvInitPyramidalAlgorithm( imgA, imgB,
766         pyrA, pyrB, level, &criteria, MAX_ITERS, flags,
767         &imgI, &imgJ, &step, &size, &scale, &pyr_buffer ));
768 
769     /* buffer_size = <size for patches> + <size for pyramids> */
770     bufferBytes = (srcPatchLen + patchLen*3)*sizeof(patchI[0]) + (36*2 + 6)*sizeof(double);
771 
772     CV_CALL( buffer = (uchar*)cvAlloc(bufferBytes));
773 
774     if( !status )
775         CV_CALL( status = _status = (char*)cvAlloc(count) );
776 
777     patchI = (float *) buffer;
778     patchJ = patchI + srcPatchLen;
779     Ix = patchJ + patchLen;
780     Iy = Ix + patchLen;
781 
782     if( status )
783         memset( status, 1, count );
784 
785     if( !(flags & CV_LKFLOW_INITIAL_GUESSES) )
786     {
787         memcpy( featuresB, featuresA, count * sizeof( featuresA[0] ));
788         for( i = 0; i < count * 4; i += 4 )
789         {
790             matrices[i] = matrices[i + 3] = 1.f;
791             matrices[i + 1] = matrices[i + 2] = 0.f;
792         }
793     }
794 
795     for( i = 0; i < count; i++ )
796     {
797         featuresB[i].x = (float)(featuresB[i].x * scale[level] * 0.5);
798         featuresB[i].y = (float)(featuresB[i].y * scale[level] * 0.5);
799     }
800 
801     /* do processing from top pyramid level (smallest image)
802        to the bottom (original image) */
803     for( l = level; l >= 0; l-- )
804     {
805         CvSize levelSize = size[l];
806         int levelStep = step[l];
807 
808         /* find flow for each given point at the particular level */
809         for( i = 0; i < count; i++ )
810         {
811             CvPoint2D32f u;
812             float Av[6];
813             double G[36];
814             double meanI = 0, meanJ = 0;
815             int x, y;
816             int pt_status = status[i];
817             CvMat mat;
818 
819             if( !pt_status )
820                 continue;
821 
822             Av[0] = matrices[i*4];
823             Av[1] = matrices[i*4+1];
824             Av[3] = matrices[i*4+2];
825             Av[4] = matrices[i*4+3];
826 
827             Av[2] = featuresB[i].x += featuresB[i].x;
828             Av[5] = featuresB[i].y += featuresB[i].y;
829 
830             u.x = (float) (featuresA[i].x * scale[l]);
831             u.y = (float) (featuresA[i].y * scale[l]);
832 
833             if( u.x < -eps || u.x >= levelSize.width+eps ||
834                 u.y < -eps || u.y >= levelSize.height+eps ||
835                 icvGetRectSubPix_8u32f_C1R( imgI[l], levelStep,
836                 levelSize, patchI, srcPatchStep, srcPatchSize, u ) < 0 )
837             {
838                 /* point is outside the image. take the next */
839                 if( l == 0 )
840                     status[i] = 0;
841                 continue;
842             }
843 
844             icvCalcIxIy_32f( patchI, srcPatchStep, Ix, Iy,
845                 (srcPatchSize.width-2)*sizeof(patchI[0]), srcPatchSize,
846                 smoothKernel, patchJ );
847 
848             /* repack patchI (remove borders) */
849             for( k = 0; k < patchSize.height; k++ )
850                 memcpy( patchI + k * patchSize.width,
851                         patchI + (k + 1) * srcPatchSize.width + 1, patchStep );
852 
853             memset( G, 0, sizeof( G ));
854 
855             /* calculate G matrix */
856             for( y = -winSize.height, k = 0; y <= winSize.height; y++ )
857             {
858                 for( x = -winSize.width; x <= winSize.width; x++, k++ )
859                 {
860                     double ixix = ((double) Ix[k]) * Ix[k];
861                     double ixiy = ((double) Ix[k]) * Iy[k];
862                     double iyiy = ((double) Iy[k]) * Iy[k];
863 
864                     double xx, xy, yy;
865 
866                     G[0] += ixix;
867                     G[1] += ixiy;
868                     G[2] += x * ixix;
869                     G[3] += y * ixix;
870                     G[4] += x * ixiy;
871                     G[5] += y * ixiy;
872 
873                     // G[6] == G[1]
874                     G[7] += iyiy;
875                     // G[8] == G[4]
876                     // G[9] == G[5]
877                     G[10] += x * iyiy;
878                     G[11] += y * iyiy;
879 
880                     xx = x * x;
881                     xy = x * y;
882                     yy = y * y;
883 
884                     // G[12] == G[2]
885                     // G[13] == G[8] == G[4]
886                     G[14] += xx * ixix;
887                     G[15] += xy * ixix;
888                     G[16] += xx * ixiy;
889                     G[17] += xy * ixiy;
890 
891                     // G[18] == G[3]
892                     // G[19] == G[9]
893                     // G[20] == G[15]
894                     G[21] += yy * ixix;
895                     // G[22] == G[17]
896                     G[23] += yy * ixiy;
897 
898                     // G[24] == G[4]
899                     // G[25] == G[10]
900                     // G[26] == G[16]
901                     // G[27] == G[22]
902                     G[28] += xx * iyiy;
903                     G[29] += xy * iyiy;
904 
905                     // G[30] == G[5]
906                     // G[31] == G[11]
907                     // G[32] == G[17]
908                     // G[33] == G[23]
909                     // G[34] == G[29]
910                     G[35] += yy * iyiy;
911 
912                     meanI += patchI[k];
913                 }
914             }
915 
916             meanI /= patchSize.width*patchSize.height;
917 
918             G[8] = G[4];
919             G[9] = G[5];
920             G[22] = G[17];
921 
922             // fill part of G below its diagonal
923             for( y = 1; y < 6; y++ )
924                 for( x = 0; x < y; x++ )
925                     G[y * 6 + x] = G[x * 6 + y];
926 
927             cvInitMatHeader( &mat, 6, 6, CV_64FC1, G );
928 
929             if( cvInvert( &mat, &mat, CV_SVD ) < 1e-4 )
930             {
931                 /* bad matrix. take the next point */
932                 if( l == 0 )
933                     status[i] = 0;
934                 continue;
935             }
936 
937             for( j = 0; j < criteria.max_iter; j++ )
938             {
939                 double b[6] = {0,0,0,0,0,0}, eta[6];
940                 double t0, t1, s = 0;
941 
942                 if( Av[2] < -eps || Av[2] >= levelSize.width+eps ||
943                     Av[5] < -eps || Av[5] >= levelSize.height+eps ||
944                     icvGetQuadrangleSubPix_8u32f_C1R( imgJ[l], levelStep,
945                     levelSize, patchJ, patchStep, patchSize, Av ) < 0 )
946                 {
947                     pt_status = 0;
948                     break;
949                 }
950 
951                 for( y = -winSize.height, k = 0, meanJ = 0; y <= winSize.height; y++ )
952                     for( x = -winSize.width; x <= winSize.width; x++, k++ )
953                         meanJ += patchJ[k];
954 
955                 meanJ = meanJ / (patchSize.width * patchSize.height) - meanI;
956 
957                 for( y = -winSize.height, k = 0; y <= winSize.height; y++ )
958                 {
959                     for( x = -winSize.width; x <= winSize.width; x++, k++ )
960                     {
961                         double t = patchI[k] - patchJ[k] + meanJ;
962                         double ixt = Ix[k] * t;
963                         double iyt = Iy[k] * t;
964 
965                         s += t;
966 
967                         b[0] += ixt;
968                         b[1] += iyt;
969                         b[2] += x * ixt;
970                         b[3] += y * ixt;
971                         b[4] += x * iyt;
972                         b[5] += y * iyt;
973                     }
974                 }
975 
976                 icvTransformVector_64d( G, b, eta, 6, 6 );
977 
978                 Av[2] = (float)(Av[2] + Av[0] * eta[0] + Av[1] * eta[1]);
979                 Av[5] = (float)(Av[5] + Av[3] * eta[0] + Av[4] * eta[1]);
980 
981                 t0 = Av[0] * (1 + eta[2]) + Av[1] * eta[4];
982                 t1 = Av[0] * eta[3] + Av[1] * (1 + eta[5]);
983                 Av[0] = (float)t0;
984                 Av[1] = (float)t1;
985 
986                 t0 = Av[3] * (1 + eta[2]) + Av[4] * eta[4];
987                 t1 = Av[3] * eta[3] + Av[4] * (1 + eta[5]);
988                 Av[3] = (float)t0;
989                 Av[4] = (float)t1;
990 
991                 if( eta[0] * eta[0] + eta[1] * eta[1] < criteria.epsilon )
992                     break;
993             }
994 
995             if( pt_status != 0 || l == 0 )
996             {
997                 status[i] = (char)pt_status;
998                 featuresB[i].x = Av[2];
999                 featuresB[i].y = Av[5];
1000 
1001                 matrices[i*4] = Av[0];
1002                 matrices[i*4+1] = Av[1];
1003                 matrices[i*4+2] = Av[3];
1004                 matrices[i*4+3] = Av[4];
1005             }
1006 
1007             if( pt_status && l == 0 && error )
1008             {
1009                 /* calc error */
1010                 double err = 0;
1011 
1012                 for( y = 0, k = 0; y < patchSize.height; y++ )
1013                 {
1014                     for( x = 0; x < patchSize.width; x++, k++ )
1015                     {
1016                         double t = patchI[k] - patchJ[k] + meanJ;
1017                         err += t * t;
1018                     }
1019                 }
1020                 error[i] = (float)sqrt(err);
1021             }
1022         }
1023     }
1024 
1025     __END__;
1026 
1027     cvFree( &pyr_buffer );
1028     cvFree( &buffer );
1029     cvFree( &_status );
1030 }
1031 
1032 
1033 
1034 static void
icvGetRTMatrix(const CvPoint2D32f * a,const CvPoint2D32f * b,int count,CvMat * M,int full_affine)1035 icvGetRTMatrix( const CvPoint2D32f* a, const CvPoint2D32f* b,
1036                 int count, CvMat* M, int full_affine )
1037 {
1038     if( full_affine )
1039     {
1040         double sa[36], sb[6];
1041         CvMat A = cvMat( 6, 6, CV_64F, sa ), B = cvMat( 6, 1, CV_64F, sb );
1042         CvMat MM = cvMat( 6, 1, CV_64F, M->data.db );
1043 
1044         int i;
1045 
1046         memset( sa, 0, sizeof(sa) );
1047         memset( sb, 0, sizeof(sb) );
1048 
1049         for( i = 0; i < count; i++ )
1050         {
1051             sa[0] += a[i].x*a[i].x;
1052             sa[1] += a[i].y*a[i].x;
1053             sa[2] += a[i].x;
1054 
1055             sa[6] += a[i].x*a[i].y;
1056             sa[7] += a[i].y*a[i].y;
1057             sa[8] += a[i].y;
1058 
1059             sa[12] += a[i].x;
1060             sa[13] += a[i].y;
1061             sa[14] += 1;
1062 
1063             sb[0] += a[i].x*b[i].x;
1064             sb[1] += a[i].y*b[i].x;
1065             sb[2] += b[i].x;
1066             sb[3] += a[i].x*b[i].y;
1067             sb[4] += a[i].y*b[i].y;
1068             sb[5] += b[i].y;
1069         }
1070 
1071         sa[21] = sa[0];
1072         sa[22] = sa[1];
1073         sa[23] = sa[2];
1074         sa[27] = sa[6];
1075         sa[28] = sa[7];
1076         sa[29] = sa[8];
1077         sa[33] = sa[12];
1078         sa[34] = sa[13];
1079         sa[35] = sa[14];
1080 
1081         cvSolve( &A, &B, &MM, CV_SVD );
1082     }
1083     else
1084     {
1085         double sa[16], sb[4], m[4], *om = M->data.db;
1086         CvMat A = cvMat( 4, 4, CV_64F, sa ), B = cvMat( 4, 1, CV_64F, sb );
1087         CvMat MM = cvMat( 4, 1, CV_64F, m );
1088 
1089         int i;
1090 
1091         memset( sa, 0, sizeof(sa) );
1092         memset( sb, 0, sizeof(sb) );
1093 
1094         for( i = 0; i < count; i++ )
1095         {
1096             sa[0] += a[i].x*a[i].x + a[i].y*a[i].y;
1097             sa[1] += 0;
1098             sa[2] += a[i].x;
1099             sa[3] += a[i].y;
1100 
1101             sa[4] += 0;
1102             sa[5] += a[i].x*a[i].x + a[i].y*a[i].y;
1103             sa[6] += -a[i].y;
1104             sa[7] += a[i].x;
1105 
1106             sa[8] += a[i].x;
1107             sa[9] += -a[i].y;
1108             sa[10] += 1;
1109             sa[11] += 0;
1110 
1111             sa[12] += a[i].y;
1112             sa[13] += a[i].x;
1113             sa[14] += 0;
1114             sa[15] += 1;
1115 
1116             sb[0] += a[i].x*b[i].x + a[i].y*b[i].y;
1117             sb[1] += a[i].x*b[i].y - a[i].y*b[i].x;
1118             sb[2] += b[i].x;
1119             sb[3] += b[i].y;
1120         }
1121 
1122         cvSolve( &A, &B, &MM, CV_SVD );
1123 
1124         om[0] = om[4] = m[0];
1125         om[1] = -m[1];
1126         om[3] = m[1];
1127         om[2] = m[2];
1128         om[5] = m[3];
1129     }
1130 }
1131 
1132 
1133 CV_IMPL int
cvEstimateRigidTransform(const CvArr * _A,const CvArr * _B,CvMat * _M,int full_affine)1134 cvEstimateRigidTransform( const CvArr* _A, const CvArr* _B, CvMat* _M, int full_affine )
1135 {
1136     int result = 0;
1137 
1138     const int COUNT = 15;
1139     const int WIDTH = 160, HEIGHT = 120;
1140     const int RANSAC_MAX_ITERS = 100;
1141     const int RANSAC_SIZE0 = 3;
1142     const double MIN_TRIANGLE_SIDE = 20;
1143     const double RANSAC_GOOD_RATIO = 0.5;
1144 
1145     int allocated = 1;
1146     CvMat *sA = 0, *sB = 0;
1147     CvPoint2D32f *pA = 0, *pB = 0;
1148     int* good_idx = 0;
1149     char *status = 0;
1150     CvMat* gray = 0;
1151 
1152     CV_FUNCNAME( "cvEstimateRigidTransform" );
1153 
1154     __BEGIN__;
1155 
1156     CvMat stubA, *A;
1157     CvMat stubB, *B;
1158     CvSize sz0, sz1;
1159     int cn, equal_sizes;
1160     int i, j, k, k1;
1161     int count_x, count_y, count;
1162     double scale = 1;
1163     CvRNG rng = cvRNG(-1);
1164     double m[6]={0};
1165     CvMat M = cvMat( 2, 3, CV_64F, m );
1166     int good_count = 0;
1167 
1168     CV_CALL( A = cvGetMat( _A, &stubA ));
1169     CV_CALL( B = cvGetMat( _B, &stubB ));
1170 
1171     if( !CV_IS_MAT(_M) )
1172         CV_ERROR( _M ? CV_StsBadArg : CV_StsNullPtr, "Output parameter M is not a valid matrix" );
1173 
1174     if( !CV_ARE_SIZES_EQ( A, B ) )
1175         CV_ERROR( CV_StsUnmatchedSizes, "Both input images must have the same size" );
1176 
1177     if( !CV_ARE_TYPES_EQ( A, B ) )
1178         CV_ERROR( CV_StsUnmatchedFormats, "Both input images must have the same data type" );
1179 
1180     if( CV_MAT_TYPE(A->type) == CV_8UC1 || CV_MAT_TYPE(A->type) == CV_8UC3 )
1181     {
1182         cn = CV_MAT_CN(A->type);
1183         sz0 = cvGetSize(A);
1184         sz1 = cvSize(WIDTH, HEIGHT);
1185 
1186         scale = MAX( (double)sz1.width/sz0.width, (double)sz1.height/sz0.height );
1187         scale = MIN( scale, 1. );
1188         sz1.width = cvRound( sz0.width * scale );
1189         sz1.height = cvRound( sz0.height * scale );
1190 
1191         equal_sizes = sz1.width == sz0.width && sz1.height == sz0.height;
1192 
1193         if( !equal_sizes || cn != 1 )
1194         {
1195             CV_CALL( sA = cvCreateMat( sz1.height, sz1.width, CV_8UC1 ));
1196             CV_CALL( sB = cvCreateMat( sz1.height, sz1.width, CV_8UC1 ));
1197 
1198             if( !equal_sizes && cn != 1 )
1199                 CV_CALL( gray = cvCreateMat( sz0.height, sz0.width, CV_8UC1 ));
1200 
1201             if( gray )
1202             {
1203                 cvCvtColor( A, gray, CV_BGR2GRAY );
1204                 cvResize( gray, sA, CV_INTER_AREA );
1205                 cvCvtColor( B, gray, CV_BGR2GRAY );
1206                 cvResize( gray, sB, CV_INTER_AREA );
1207             }
1208             else if( cn == 1 )
1209             {
1210                 cvResize( gray, sA, CV_INTER_AREA );
1211                 cvResize( gray, sB, CV_INTER_AREA );
1212             }
1213             else
1214             {
1215                 cvCvtColor( A, gray, CV_BGR2GRAY );
1216                 cvResize( gray, sA, CV_INTER_AREA );
1217                 cvCvtColor( B, gray, CV_BGR2GRAY );
1218             }
1219 
1220             cvReleaseMat( &gray );
1221             A = sA;
1222             B = sB;
1223         }
1224 
1225         count_y = COUNT;
1226         count_x = cvRound((double)COUNT*sz1.width/sz1.height);
1227         count = count_x * count_y;
1228 
1229         CV_CALL( pA = (CvPoint2D32f*)cvAlloc( count*sizeof(pA[0]) ));
1230         CV_CALL( pB = (CvPoint2D32f*)cvAlloc( count*sizeof(pB[0]) ));
1231         CV_CALL( status = (char*)cvAlloc( count*sizeof(status[0]) ));
1232 
1233         for( i = 0, k = 0; i < count_y; i++ )
1234             for( j = 0; j < count_x; j++, k++ )
1235             {
1236                 pA[k].x = (j+0.5f)*sz1.width/count_x;
1237                 pA[k].y = (i+0.5f)*sz1.height/count_y;
1238             }
1239 
1240         // find the corresponding points in B
1241         cvCalcOpticalFlowPyrLK( A, B, 0, 0, pA, pB, count, cvSize(10,10), 3,
1242                                 status, 0, cvTermCriteria(CV_TERMCRIT_ITER,40,0.1), 0 );
1243 
1244         // repack the remained points
1245         for( i = 0, k = 0; i < count; i++ )
1246             if( status[i] )
1247             {
1248                 if( i > k )
1249                 {
1250                     pA[k] = pA[i];
1251                     pB[k] = pB[i];
1252                 }
1253                 k++;
1254             }
1255 
1256         count = k;
1257     }
1258     else if( CV_MAT_TYPE(A->type) == CV_32FC2 || CV_MAT_TYPE(A->type) == CV_32SC2 )
1259     {
1260         count = A->cols*A->rows;
1261 
1262         if( CV_IS_MAT_CONT(A->type & B->type) && CV_MAT_TYPE(A->type) == CV_32FC2 )
1263         {
1264             pA = (CvPoint2D32f*)A->data.ptr;
1265             pB = (CvPoint2D32f*)B->data.ptr;
1266             allocated = 0;
1267         }
1268         else
1269         {
1270             CvMat _pA, _pB;
1271 
1272             CV_CALL( pA = (CvPoint2D32f*)cvAlloc( count*sizeof(pA[0]) ));
1273             CV_CALL( pB = (CvPoint2D32f*)cvAlloc( count*sizeof(pB[0]) ));
1274             _pA = cvMat( A->rows, A->cols, CV_32FC2, pA );
1275             _pB = cvMat( B->rows, B->cols, CV_32FC2, pB );
1276             cvConvert( A, &_pA );
1277             cvConvert( B, &_pB );
1278         }
1279     }
1280     else
1281         CV_ERROR( CV_StsUnsupportedFormat, "Both input images must have either 8uC1 or 8uC3 type" );
1282 
1283     CV_CALL( good_idx = (int*)cvAlloc( count*sizeof(good_idx[0]) ));
1284 
1285     if( count < RANSAC_SIZE0 )
1286         EXIT;
1287 
1288     // RANSAC stuff:
1289     // 1. find the consensus
1290     for( k = 0; k < RANSAC_MAX_ITERS; k++ )
1291     {
1292         int idx[RANSAC_SIZE0];
1293         CvPoint2D32f a[3];
1294         CvPoint2D32f b[3];
1295 
1296         memset( a, 0, sizeof(a) );
1297         memset( b, 0, sizeof(b) );
1298 
1299         // choose random 3 non-complanar points from A & B
1300         for( i = 0; i < RANSAC_SIZE0; i++ )
1301         {
1302             for( k1 = 0; k1 < RANSAC_MAX_ITERS; k1++ )
1303             {
1304                 idx[i] = cvRandInt(&rng) % count;
1305 
1306                 for( j = 0; j < i; j++ )
1307                 {
1308                     if( idx[j] == idx[i] )
1309                         break;
1310                     // check that the points are not very close one each other
1311                     if( fabs(pA[idx[i]].x - pA[idx[j]].x) +
1312                         fabs(pA[idx[i]].y - pA[idx[j]].y) < MIN_TRIANGLE_SIDE )
1313                         break;
1314                     if( fabs(pB[idx[i]].x - pB[idx[j]].x) +
1315                         fabs(pB[idx[i]].y - pB[idx[j]].y) < MIN_TRIANGLE_SIDE )
1316                         break;
1317                 }
1318 
1319                 if( j < i )
1320                     continue;
1321 
1322                 if( i+1 == RANSAC_SIZE0 )
1323                 {
1324                     // additional check for non-complanar vectors
1325                     a[0] = pA[idx[0]];
1326                     a[1] = pA[idx[1]];
1327                     a[2] = pA[idx[2]];
1328 
1329                     b[0] = pB[idx[0]];
1330                     b[1] = pB[idx[1]];
1331                     b[2] = pB[idx[2]];
1332 
1333                     if( fabs((a[1].x - a[0].x)*(a[2].y - a[0].y) - (a[1].y - a[0].y)*(a[2].x - a[0].x)) < 1 ||
1334                         fabs((b[1].x - b[0].x)*(b[2].y - b[0].y) - (b[1].y - b[0].y)*(b[2].x - b[0].x)) < 1 )
1335                         continue;
1336                 }
1337                 break;
1338             }
1339 
1340             if( k1 >= RANSAC_MAX_ITERS )
1341                 break;
1342         }
1343 
1344         if( i < RANSAC_SIZE0 )
1345             continue;
1346 
1347         // estimate the transformation using 3 points
1348         icvGetRTMatrix( a, b, 3, &M, full_affine );
1349 
1350         for( i = 0, good_count = 0; i < count; i++ )
1351         {
1352             if( fabs( m[0]*pA[i].x + m[1]*pA[i].y + m[2] - pB[i].x ) +
1353                 fabs( m[3]*pA[i].x + m[4]*pA[i].y + m[5] - pB[i].y ) < 8 )
1354                 good_idx[good_count++] = i;
1355         }
1356 
1357         if( good_count >= count*RANSAC_GOOD_RATIO )
1358             break;
1359     }
1360 
1361     if( k >= RANSAC_MAX_ITERS )
1362         EXIT;
1363 
1364     if( good_count < count )
1365     {
1366         for( i = 0; i < good_count; i++ )
1367         {
1368             j = good_idx[i];
1369             pA[i] = pA[j];
1370             pB[i] = pB[j];
1371         }
1372     }
1373 
1374     icvGetRTMatrix( pA, pB, good_count, &M, full_affine );
1375     m[2] /= scale;
1376     m[5] /= scale;
1377     CV_CALL( cvConvert( &M, _M ));
1378     result = 1;
1379 
1380     __END__;
1381 
1382     cvReleaseMat( &sA );
1383     cvReleaseMat( &sB );
1384     cvFree( &pA );
1385     cvFree( &pB );
1386     cvFree( &status );
1387     cvFree( &good_idx );
1388     cvReleaseMat( &gray );
1389 
1390     return result;
1391 }
1392 
1393 
1394 /* End of file. */
1395