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     11 //                For Open Source Computer Vision Library
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     40 //M*/
     41 #include "_cv.h"
     42 #include <float.h>
     43 #include <stdio.h>
     44 
     45 static void
     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 
     67 static int icvMinimalPyramidSize( CvSize imgSize )
     68 {
     69     return cvAlign(imgSize.width,8) * imgSize.height / 3;
     70 }
     71 
     72 
     73 static void
     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
    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
    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
    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
   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
   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