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     41 
     42 /****************************************************************************************\
     43 *    Very fast SAD-based (Sum-of-Absolute-Diffrences) stereo correspondence algorithm.   *
     44 *    Contributed by Kurt Konolige                                                        *
     45 \****************************************************************************************/
     46 
     47 #include "_cv.h"
     48 /*
     49 #undef CV_SSE2
     50 #define CV_SSE2 1
     51 #include "emmintrin.h"
     52 */
     53 
     54 CV_IMPL CvStereoBMState*
     55 cvCreateStereoBMState( int /*preset*/, int numberOfDisparities )
     56 {
     57     CvStereoBMState* state = 0;
     58 
     59     //CV_FUNCNAME( "cvCreateStereoBMState" );
     60 
     61     __BEGIN__;
     62 
     63     state = (CvStereoBMState*)cvAlloc( sizeof(*state) );
     64     if( !state )
     65         EXIT;
     66 
     67     state->preFilterType = CV_STEREO_BM_NORMALIZED_RESPONSE;
     68     state->preFilterSize = 9;
     69     state->preFilterCap = 31;
     70     state->SADWindowSize = 15;
     71     state->minDisparity = 0;
     72     state->numberOfDisparities = numberOfDisparities > 0 ? numberOfDisparities : 64;
     73     state->textureThreshold = 10;
     74     state->uniquenessRatio = 15;
     75     state->speckleRange = state->speckleWindowSize = 0;
     76 
     77     state->preFilteredImg0 = state->preFilteredImg1 = state->slidingSumBuf = 0;
     78 
     79     __END__;
     80 
     81     if( cvGetErrStatus() < 0 )
     82         cvReleaseStereoBMState( &state );
     83     return state;
     84 }
     85 
     86 
     87 CV_IMPL void
     88 cvReleaseStereoBMState( CvStereoBMState** state )
     89 {
     90     CV_FUNCNAME( "cvReleaseStereoBMState" );
     91 
     92     __BEGIN__;
     93 
     94     if( !state )
     95         CV_ERROR( CV_StsNullPtr, "" );
     96 
     97     if( !*state )
     98         EXIT;
     99 
    100     cvReleaseMat( &(*state)->preFilteredImg0 );
    101     cvReleaseMat( &(*state)->preFilteredImg1 );
    102     cvReleaseMat( &(*state)->slidingSumBuf );
    103     cvFree( state );
    104 
    105     __END__;
    106 }
    107 
    108 static void icvPrefilter( const CvMat* src, CvMat* dst, int winsize, int ftzero, uchar* buf )
    109 {
    110     int x, y, wsz2 = winsize/2;
    111     int* vsum = (int*)cvAlignPtr(buf + (wsz2 + 1)*sizeof(vsum[0]), 32);
    112     int scale_g = winsize*winsize/8, scale_s = (1024 + scale_g)/(scale_g*2);
    113     const int OFS = 256*5, TABSZ = OFS*2 + 256;
    114     uchar tab[TABSZ];
    115     const uchar* sptr = src->data.ptr;
    116     int srcstep = src->step;
    117     CvSize size = cvGetMatSize(src);
    118 
    119     scale_g *= scale_s;
    120 
    121     for( x = 0; x < TABSZ; x++ )
    122         tab[x] = (uchar)(x - OFS < -ftzero ? 0 : x - OFS > ftzero ? ftzero*2 : x - OFS + ftzero);
    123 
    124     for( x = 0; x < size.width; x++ )
    125         vsum[x] = (ushort)(sptr[x]*(wsz2 + 2));
    126 
    127     for( y = 1; y < wsz2; y++ )
    128     {
    129         for( x = 0; x < size.width; x++ )
    130             vsum[x] = (ushort)(vsum[x] + sptr[srcstep*y + x]);
    131     }
    132 
    133     for( y = 0; y < size.height; y++ )
    134     {
    135         const uchar* top = sptr + srcstep*MAX(y-wsz2-1,0);
    136         const uchar* bottom = sptr + srcstep*MIN(y+wsz2,size.height-1);
    137         const uchar* prev = sptr + srcstep*MAX(y-1,0);
    138         const uchar* curr = sptr + srcstep*y;
    139         const uchar* next = sptr + srcstep*MIN(y+1,size.height-1);
    140         uchar* dptr = dst->data.ptr + dst->step*y;
    141         x = 0;
    142 
    143         for( ; x < size.width; x++ )
    144             vsum[x] = (ushort)(vsum[x] + bottom[x] - top[x]);
    145 
    146         for( x = 0; x <= wsz2; x++ )
    147         {
    148             vsum[-x-1] = vsum[0];
    149             vsum[size.width+x] = vsum[size.width-1];
    150         }
    151 
    152         int sum = vsum[0]*(wsz2 + 1);
    153         for( x = 1; x <= wsz2; x++ )
    154             sum += vsum[x];
    155 
    156         int val = ((curr[0]*5 + curr[1] + prev[0] + next[0])*scale_g - sum*scale_s) >> 10;
    157         dptr[0] = tab[val + OFS];
    158 
    159         for( x = 1; x < size.width-1; x++ )
    160         {
    161             sum += vsum[x+wsz2] - vsum[x-wsz2-1];
    162             val = ((curr[x]*4 + curr[x-1] + curr[x+1] + prev[x] + next[x])*scale_g - sum*scale_s) >> 10;
    163             dptr[x] = tab[val + OFS];
    164         }
    165 
    166         sum += vsum[x+wsz2] - vsum[x-wsz2-1];
    167         val = ((curr[x]*5 + curr[x-1] + prev[x] + next[x])*scale_g - sum*scale_s) >> 10;
    168         dptr[x] = tab[val + OFS];
    169     }
    170 }
    171 
    172 
    173 static const int DISPARITY_SHIFT = 4;
    174 
    175 #if CV_SSE2
    176 static void
    177 icvFindStereoCorrespondenceBM_SSE2( const CvMat* left, const CvMat* right,
    178                                     CvMat* disp, CvStereoBMState* state,
    179                                     uchar* buf, int _dy0, int _dy1 )
    180 {
    181     int x, y, d;
    182     int wsz = state->SADWindowSize, wsz2 = wsz/2;
    183     int dy0 = MIN(_dy0, wsz2+1), dy1 = MIN(_dy1, wsz2+1);
    184     int ndisp = state->numberOfDisparities;
    185     int mindisp = state->minDisparity;
    186     int lofs = MAX(ndisp - 1 + mindisp, 0);
    187     int rofs = -MIN(ndisp - 1 + mindisp, 0);
    188     int width = left->cols, height = left->rows;
    189     int width1 = width - rofs - ndisp + 1;
    190     int ftzero = state->preFilterCap;
    191     int textureThreshold = state->textureThreshold;
    192     int uniquenessRatio = state->uniquenessRatio;
    193     short FILTERED = (short)((mindisp - 1) << DISPARITY_SHIFT);
    194 
    195     ushort *sad, *hsad0, *hsad, *hsad_sub;
    196     int *htext;
    197     uchar *cbuf0, *cbuf;
    198     const uchar* lptr0 = left->data.ptr + lofs;
    199     const uchar* rptr0 = right->data.ptr + rofs;
    200     const uchar *lptr, *lptr_sub, *rptr;
    201     short* dptr = disp->data.s;
    202     int sstep = left->step;
    203     int dstep = disp->step/sizeof(dptr[0]);
    204     int cstep = (height + dy0 + dy1)*ndisp;
    205     const int TABSZ = 256;
    206     uchar tab[TABSZ];
    207     const __m128i d0_8 = _mm_setr_epi16(0,1,2,3,4,5,6,7), dd_8 = _mm_set1_epi16(8);
    208 
    209     sad = (ushort*)cvAlignPtr(buf + sizeof(sad[0]));
    210     hsad0 = (ushort*)cvAlignPtr(sad + ndisp + 1 + dy0*ndisp);
    211     htext = (int*)cvAlignPtr((int*)(hsad0 + (height+dy1)*ndisp) + wsz2 + 2);
    212     cbuf0 = (uchar*)cvAlignPtr(htext + height + wsz2 + 2 + dy0*ndisp);
    213 
    214     for( x = 0; x < TABSZ; x++ )
    215         tab[x] = (uchar)abs(x - ftzero);
    216 
    217     // initialize buffers
    218     memset( hsad0 - dy0*ndisp, 0, (height + dy0 + dy1)*ndisp*sizeof(hsad0[0]) );
    219     memset( htext - wsz2 - 1, 0, (height + wsz + 1)*sizeof(htext[0]) );
    220 
    221     for( x = -wsz2-1; x < wsz2; x++ )
    222     {
    223         hsad = hsad0 - dy0*ndisp; cbuf = cbuf0 + (x + wsz2 + 1)*cstep - dy0*ndisp;
    224         lptr = lptr0 + MIN(MAX(x, -lofs), width-lofs-1) - dy0*sstep;
    225         rptr = rptr0 + MIN(MAX(x, -rofs), width-rofs-1) - dy0*sstep;
    226 
    227         for( y = -dy0; y < height + dy1; y++, hsad += ndisp, cbuf += ndisp, lptr += sstep, rptr += sstep )
    228         {
    229             int lval = lptr[0];
    230             for( d = 0; d < ndisp; d++ )
    231             {
    232                 int diff = abs(lval - rptr[d]);
    233                 cbuf[d] = (uchar)diff;
    234                 hsad[d] = (ushort)(hsad[d] + diff);
    235             }
    236             htext[y] += tab[lval];
    237         }
    238     }
    239 
    240     // initialize the left and right borders of the disparity map
    241     for( y = 0; y < height; y++ )
    242     {
    243         for( x = 0; x < lofs; x++ )
    244             dptr[y*dstep + x] = FILTERED;
    245         for( x = lofs + width1; x < width; x++ )
    246             dptr[y*dstep + x] = FILTERED;
    247     }
    248     dptr += lofs;
    249 
    250     for( x = 0; x < width1; x++, dptr++ )
    251     {
    252         int x0 = x - wsz2 - 1, x1 = x + wsz2;
    253         const uchar* cbuf_sub = cbuf0 + ((x0 + wsz2 + 1) % (wsz + 1))*cstep - dy0*ndisp;
    254         uchar* cbuf = cbuf0 + ((x1 + wsz2 + 1) % (wsz + 1))*cstep - dy0*ndisp;
    255         hsad = hsad0 - dy0*ndisp;
    256         lptr_sub = lptr0 + MIN(MAX(x0, -lofs), width-1-lofs) - dy0*sstep;
    257         lptr = lptr0 + MIN(MAX(x1, -lofs), width-1-lofs) - dy0*sstep;
    258         rptr = rptr0 + MIN(MAX(x1, -rofs), width-1-rofs) - dy0*sstep;
    259 
    260         for( y = -dy0; y < height + dy1; y++, cbuf += ndisp, cbuf_sub += ndisp,
    261              hsad += ndisp, lptr += sstep, lptr_sub += sstep, rptr += sstep )
    262         {
    263             int lval = lptr[0];
    264             __m128i lv = _mm_set1_epi8((char)lval), z = _mm_setzero_si128();
    265             for( d = 0; d < ndisp; d += 16 )
    266             {
    267                 __m128i rv = _mm_loadu_si128((const __m128i*)(rptr + d));
    268                 __m128i hsad_l = _mm_load_si128((__m128i*)(hsad + d));
    269                 __m128i hsad_h = _mm_load_si128((__m128i*)(hsad + d + 8));
    270                 __m128i cbs = _mm_load_si128((const __m128i*)(cbuf_sub + d));
    271                 __m128i diff = _mm_adds_epu8(_mm_subs_epu8(lv, rv), _mm_subs_epu8(rv, lv));
    272                 __m128i diff_h = _mm_sub_epi16(_mm_unpackhi_epi8(diff, z), _mm_unpackhi_epi8(cbs, z));
    273                 _mm_store_si128((__m128i*)(cbuf + d), diff);
    274                 diff = _mm_sub_epi16(_mm_unpacklo_epi8(diff, z), _mm_unpacklo_epi8(cbs, z));
    275                 hsad_h = _mm_add_epi16(hsad_h, diff_h);
    276                 hsad_l = _mm_add_epi16(hsad_l, diff);
    277                 _mm_store_si128((__m128i*)(hsad + d), hsad_l);
    278                 _mm_store_si128((__m128i*)(hsad + d + 8), hsad_h);
    279             }
    280             htext[y] += tab[lval] - tab[lptr_sub[0]];
    281         }
    282 
    283         // fill borders
    284         for( y = dy1; y <= wsz2; y++ )
    285             htext[height+y] = htext[height+dy1-1];
    286         for( y = -wsz2-1; y < -dy0; y++ )
    287             htext[y] = htext[-dy0];
    288 
    289         // initialize sums
    290         for( d = 0; d < ndisp; d++ )
    291             sad[d] = (ushort)(hsad0[d-ndisp*dy0]*(wsz2 + 2 - dy0));
    292 
    293         hsad = hsad0 + (1 - dy0)*ndisp;
    294         for( y = 1 - dy0; y < wsz2; y++, hsad += ndisp )
    295             for( d = 0; d < ndisp; d++ )
    296                 sad[d] = (ushort)(sad[d] + hsad[d]);
    297         int tsum = 0;
    298         for( y = -wsz2-1; y < wsz2; y++ )
    299             tsum += htext[y];
    300 
    301         // finally, start the real processing
    302         for( y = 0; y < height; y++ )
    303         {
    304             int minsad = INT_MAX, mind = -1;
    305             hsad = hsad0 + MIN(y + wsz2, height+dy1-1)*ndisp;
    306             hsad_sub = hsad0 + MAX(y - wsz2 - 1, -dy0)*ndisp;
    307             __m128i minsad8 = _mm_set1_epi16(SHRT_MAX);
    308             __m128i mind8 = _mm_set1_epi16(-1), d8 = d0_8, mask;
    309 
    310             for( d = 0; d < ndisp; d += 8 )
    311             {
    312                 __m128i v0 = _mm_load_si128((__m128i*)(hsad_sub + d));
    313                 __m128i v1 = _mm_load_si128((__m128i*)(hsad + d));
    314                 __m128i sad8 = _mm_load_si128((__m128i*)(sad + d));
    315                 sad8 = _mm_sub_epi16(sad8, v0);
    316                 sad8 = _mm_add_epi16(sad8, v1);
    317 
    318                 mask = _mm_cmpgt_epi16(minsad8, sad8);
    319                 _mm_store_si128((__m128i*)(sad + d), sad8);
    320                 minsad8 = _mm_min_epi16(minsad8, sad8);
    321                 mind8 = _mm_xor_si128(mind8,_mm_and_si128(_mm_xor_si128(d8,mind8),mask));
    322                 d8 = _mm_add_epi16(d8, dd_8);
    323             }
    324 
    325             __m128i minsad82 = _mm_unpackhi_epi64(minsad8, minsad8);
    326             __m128i mind82 = _mm_unpackhi_epi64(mind8, mind8);
    327             mask = _mm_cmpgt_epi16(minsad8, minsad82);
    328             mind8 = _mm_xor_si128(mind8,_mm_and_si128(_mm_xor_si128(mind82,mind8),mask));
    329             minsad8 = _mm_min_epi16(minsad8, minsad82);
    330 
    331             minsad82 = _mm_shufflelo_epi16(minsad8, _MM_SHUFFLE(3,2,3,2));
    332             mind82 = _mm_shufflelo_epi16(mind8, _MM_SHUFFLE(3,2,3,2));
    333             mask = _mm_cmpgt_epi16(minsad8, minsad82);
    334             mind8 = _mm_xor_si128(mind8,_mm_and_si128(_mm_xor_si128(mind82,mind8),mask));
    335             minsad8 = _mm_min_epi16(minsad8, minsad82);
    336 
    337             minsad82 = _mm_shufflelo_epi16(minsad8, 1);
    338             mind82 = _mm_shufflelo_epi16(mind8, 1);
    339             mask = _mm_cmpgt_epi16(minsad8, minsad82);
    340             mind8 = _mm_xor_si128(mind8,_mm_and_si128(_mm_xor_si128(mind82,mind8),mask));
    341             mind = (short)_mm_cvtsi128_si32(mind8);
    342             minsad = sad[mind];
    343             tsum += htext[y + wsz2] - htext[y - wsz2 - 1];
    344             if( tsum < textureThreshold )
    345             {
    346                 dptr[y*dstep] = FILTERED;
    347                 continue;
    348             }
    349 
    350             if( uniquenessRatio > 0 )
    351             {
    352                 int thresh = minsad + (minsad * uniquenessRatio/100);
    353                 __m128i thresh8 = _mm_set1_epi16((short)(thresh + 1));
    354                 __m128i d1 = _mm_set1_epi16((short)(mind-1)), d2 = _mm_set1_epi16((short)(mind+1));
    355                 __m128i d8 = d0_8;
    356 
    357                 for( d = 0; d < ndisp; d += 8 )
    358                 {
    359                     __m128i sad8 = _mm_load_si128((__m128i*)(sad + d));
    360                     __m128i mask = _mm_cmpgt_epi16( thresh8, sad8 );
    361                     mask = _mm_and_si128(mask, _mm_or_si128(_mm_cmpgt_epi16(d1,d8), _mm_cmpgt_epi16(d8,d2)));
    362                     if( _mm_movemask_epi8(mask) )
    363                         break;
    364                     d8 = _mm_add_epi16(d8, dd_8);
    365                 }
    366                 if( d < ndisp )
    367                 {
    368                     dptr[y*dstep] = FILTERED;
    369                     continue;
    370                 }
    371             }
    372 
    373             {
    374             sad[-1] = sad[1];
    375             sad[ndisp] = sad[ndisp-2];
    376             int p = sad[mind+1], n = sad[mind-1], d = p + n - 2*sad[mind];
    377             dptr[y*dstep] = (short)(((ndisp - mind - 1 + mindisp)*256 + (d != 0 ? (p-n)*128/d : 0) + 15) >> 4);
    378             }
    379         }
    380     }
    381 }
    382 #endif
    383 
    384 static void
    385 icvFindStereoCorrespondenceBM( const CvMat* left, const CvMat* right,
    386                                CvMat* disp, CvStereoBMState* state,
    387                                uchar* buf, int _dy0, int _dy1 )
    388 {
    389     int x, y, d;
    390     int wsz = state->SADWindowSize, wsz2 = wsz/2;
    391     int dy0 = MIN(_dy0, wsz2+1), dy1 = MIN(_dy1, wsz2+1);
    392     int ndisp = state->numberOfDisparities;
    393     int mindisp = state->minDisparity;
    394     int lofs = MAX(ndisp - 1 + mindisp, 0);
    395     int rofs = -MIN(ndisp - 1 + mindisp, 0);
    396     int width = left->cols, height = left->rows;
    397     int width1 = width - rofs - ndisp + 1;
    398     int ftzero = state->preFilterCap;
    399     int textureThreshold = state->textureThreshold;
    400     int uniquenessRatio = state->uniquenessRatio;
    401     short FILTERED = (short)((mindisp - 1) << DISPARITY_SHIFT);
    402 
    403     int *sad, *hsad0, *hsad, *hsad_sub, *htext;
    404     uchar *cbuf0, *cbuf;
    405     const uchar* lptr0 = left->data.ptr + lofs;
    406     const uchar* rptr0 = right->data.ptr + rofs;
    407     const uchar *lptr, *lptr_sub, *rptr;
    408     short* dptr = disp->data.s;
    409     int sstep = left->step;
    410     int dstep = disp->step/sizeof(dptr[0]);
    411     int cstep = (height+dy0+dy1)*ndisp;
    412     const int TABSZ = 256;
    413     uchar tab[TABSZ];
    414 
    415     sad = (int*)cvAlignPtr(buf + sizeof(sad[0]));
    416     hsad0 = (int*)cvAlignPtr(sad + ndisp + 1 + dy0*ndisp);
    417     htext = (int*)cvAlignPtr((int*)(hsad0 + (height+dy1)*ndisp) + wsz2 + 2);
    418     cbuf0 = (uchar*)cvAlignPtr(htext + height + wsz2 + 2 + dy0*ndisp);
    419 
    420     for( x = 0; x < TABSZ; x++ )
    421         tab[x] = (uchar)abs(x - ftzero);
    422 
    423     // initialize buffers
    424     memset( hsad0 - dy0*ndisp, 0, (height + dy0 + dy1)*ndisp*sizeof(hsad0[0]) );
    425     memset( htext - wsz2 - 1, 0, (height + wsz + 1)*sizeof(htext[0]) );
    426 
    427     for( x = -wsz2-1; x < wsz2; x++ )
    428     {
    429         hsad = hsad0 - dy0*ndisp; cbuf = cbuf0 + (x + wsz2 + 1)*cstep - dy0*ndisp;
    430         lptr = lptr0 + MIN(MAX(x, -lofs), width-lofs-1) - dy0*sstep;
    431         rptr = rptr0 + MIN(MAX(x, -rofs), width-rofs-1) - dy0*sstep;
    432 
    433         for( y = -dy0; y < height + dy1; y++, hsad += ndisp, cbuf += ndisp, lptr += sstep, rptr += sstep )
    434         {
    435             int lval = lptr[0];
    436             for( d = 0; d < ndisp; d++ )
    437             {
    438                 int diff = abs(lval - rptr[d]);
    439                 cbuf[d] = (uchar)diff;
    440                 hsad[d] = (int)(hsad[d] + diff);
    441             }
    442             htext[y] += tab[lval];
    443         }
    444     }
    445 
    446     // initialize the left and right borders of the disparity map
    447     for( y = 0; y < height; y++ )
    448     {
    449         for( x = 0; x < lofs; x++ )
    450             dptr[y*dstep + x] = FILTERED;
    451         for( x = lofs + width1; x < width; x++ )
    452             dptr[y*dstep + x] = FILTERED;
    453     }
    454     dptr += lofs;
    455 
    456     for( x = 0; x < width1; x++, dptr++ )
    457     {
    458         int x0 = x - wsz2 - 1, x1 = x + wsz2;
    459         const uchar* cbuf_sub = cbuf0 + ((x0 + wsz2 + 1) % (wsz + 1))*cstep - dy0*ndisp;
    460         uchar* cbuf = cbuf0 + ((x1 + wsz2 + 1) % (wsz + 1))*cstep - dy0*ndisp;
    461         hsad = hsad0 - dy0*ndisp;
    462         lptr_sub = lptr0 + MIN(MAX(x0, -lofs), width-1-lofs) - dy0*sstep;
    463         lptr = lptr0 + MIN(MAX(x1, -lofs), width-1-lofs) - dy0*sstep;
    464         rptr = rptr0 + MIN(MAX(x1, -rofs), width-1-rofs) - dy0*sstep;
    465 
    466         for( y = -dy0; y < height + dy1; y++, cbuf += ndisp, cbuf_sub += ndisp,
    467              hsad += ndisp, lptr += sstep, lptr_sub += sstep, rptr += sstep )
    468         {
    469             int lval = lptr[0];
    470             for( d = 0; d < ndisp; d++ )
    471             {
    472                 int diff = abs(lval - rptr[d]);
    473                 cbuf[d] = (uchar)diff;
    474                 hsad[d] = hsad[d] + diff - cbuf_sub[d];
    475             }
    476             htext[y] += tab[lval] - tab[lptr_sub[0]];
    477         }
    478 
    479         // fill borders
    480         for( y = dy1; y <= wsz2; y++ )
    481             htext[height+y] = htext[height+dy1-1];
    482         for( y = -wsz2-1; y < -dy0; y++ )
    483             htext[y] = htext[-dy0];
    484 
    485         // initialize sums
    486         for( d = 0; d < ndisp; d++ )
    487             sad[d] = (int)(hsad0[d-ndisp*dy0]*(wsz2 + 2 - dy0));
    488 
    489         hsad = hsad0 + (1 - dy0)*ndisp;
    490         for( y = 1 - dy0; y < wsz2; y++, hsad += ndisp )
    491             for( d = 0; d < ndisp; d++ )
    492                 sad[d] = (int)(sad[d] + hsad[d]);
    493         int tsum = 0;
    494         for( y = -wsz2-1; y < wsz2; y++ )
    495             tsum += htext[y];
    496 
    497         // finally, start the real processing
    498         for( y = 0; y < height; y++ )
    499         {
    500             int minsad = INT_MAX, mind = -1;
    501             hsad = hsad0 + MIN(y + wsz2, height+dy1-1)*ndisp;
    502             hsad_sub = hsad0 + MAX(y - wsz2 - 1, -dy0)*ndisp;
    503 
    504             for( d = 0; d < ndisp; d++ )
    505             {
    506                 int currsad = sad[d] + hsad[d] - hsad_sub[d];
    507                 sad[d] = currsad;
    508                 if( currsad < minsad )
    509                 {
    510                     minsad = currsad;
    511                     mind = d;
    512                 }
    513             }
    514             tsum += htext[y + wsz2] - htext[y - wsz2 - 1];
    515             if( tsum < textureThreshold )
    516             {
    517                 dptr[y*dstep] = FILTERED;
    518                 continue;
    519             }
    520 
    521             if( uniquenessRatio > 0 )
    522             {
    523                 int thresh = minsad + (minsad * uniquenessRatio/100);
    524                 for( d = 0; d < ndisp; d++ )
    525                 {
    526                     if( sad[d] <= thresh && (d < mind-1 || d > mind+1))
    527                         break;
    528                 }
    529                 if( d < ndisp )
    530                 {
    531                     dptr[y*dstep] = FILTERED;
    532                     continue;
    533                 }
    534             }
    535 
    536             {
    537             sad[-1] = sad[1];
    538             sad[ndisp] = sad[ndisp-2];
    539             int p = sad[mind+1], n = sad[mind-1], d = p + n - 2*sad[mind];
    540             dptr[y*dstep] = (short)(((ndisp - mind - 1 + mindisp)*256 + (d != 0 ? (p-n)*128/d : 0) + 15) >> 4);
    541             }
    542         }
    543     }
    544 }
    545 
    546 
    547 CV_IMPL void
    548 cvFindStereoCorrespondenceBM( const CvArr* leftarr, const CvArr* rightarr,
    549                               CvArr* disparr, CvStereoBMState* state )
    550 {
    551     CV_FUNCNAME( "cvFindStereoCorrespondenceBM" );
    552 
    553     __BEGIN__;
    554 
    555     CvMat lstub, *left0 = cvGetMat( leftarr, &lstub );
    556     CvMat rstub, *right0 = cvGetMat( rightarr, &rstub );
    557     CvMat left, right;
    558     CvMat dstub, *disp = cvGetMat( disparr, &dstub );
    559     int bufSize0, bufSize1, bufSize, width, width1, height;
    560     int wsz, ndisp, mindisp, lofs, rofs;
    561     int i, n = cvGetNumThreads();
    562 
    563     if( !CV_ARE_SIZES_EQ(left0, right0) ||
    564         !CV_ARE_SIZES_EQ(disp, left0) )
    565         CV_ERROR( CV_StsUnmatchedSizes, "All the images must have the same size" );
    566 
    567     if( CV_MAT_TYPE(left0->type) != CV_8UC1 ||
    568         !CV_ARE_TYPES_EQ(left0, right0) ||
    569         CV_MAT_TYPE(disp->type) != CV_16SC1 )
    570         CV_ERROR( CV_StsUnsupportedFormat,
    571         "Both input images must have 8uC1 format and the disparity image must have 16sC1 format" );
    572 
    573     if( !state )
    574         CV_ERROR( CV_StsNullPtr, "Stereo BM state is NULL." );
    575 
    576     if( state->preFilterType != CV_STEREO_BM_NORMALIZED_RESPONSE )
    577         CV_ERROR( CV_StsOutOfRange, "preFilterType must be =CV_STEREO_BM_NORMALIZED_RESPONSE" );
    578 
    579     if( state->preFilterSize < 5 || state->preFilterSize > 255 || state->preFilterSize % 2 == 0 )
    580         CV_ERROR( CV_StsOutOfRange, "preFilterSize must be odd and be within 5..255" );
    581 
    582     if( state->preFilterCap < 1 || state->preFilterCap > 63 )
    583         CV_ERROR( CV_StsOutOfRange, "preFilterCap must be within 1..63" );
    584 
    585     if( state->SADWindowSize < 5 || state->SADWindowSize > 255 || state->SADWindowSize % 2 == 0 ||
    586         state->SADWindowSize >= MIN(left0->cols, left0->rows) )
    587         CV_ERROR( CV_StsOutOfRange, "SADWindowSize must be odd, be within 5..255 and "
    588                                     "be not larger than image width or height" );
    589 
    590     if( state->numberOfDisparities <= 0 || state->numberOfDisparities % 16 != 0 )
    591         CV_ERROR( CV_StsOutOfRange, "numberOfDisparities must be positive and divisble by 16" );
    592     if( state->textureThreshold < 0 )
    593         CV_ERROR( CV_StsOutOfRange, "texture threshold must be non-negative" );
    594     if( state->uniquenessRatio < 0 )
    595         CV_ERROR( CV_StsOutOfRange, "uniqueness ratio must be non-negative" );
    596 
    597     if( !state->preFilteredImg0 ||
    598         state->preFilteredImg0->cols*state->preFilteredImg0->rows < left0->cols*left0->rows )
    599     {
    600         cvReleaseMat( &state->preFilteredImg0 );
    601         cvReleaseMat( &state->preFilteredImg1 );
    602 
    603         state->preFilteredImg0 = cvCreateMat( left0->rows, left0->cols, CV_8U );
    604         state->preFilteredImg1 = cvCreateMat( left0->rows, left0->cols, CV_8U );
    605     }
    606     left = cvMat(left0->rows, left0->cols, CV_8U, state->preFilteredImg0->data.ptr);
    607     right = cvMat(right0->rows, right0->cols, CV_8U, state->preFilteredImg1->data.ptr);
    608 
    609     mindisp = state->minDisparity;
    610     ndisp = state->numberOfDisparities;
    611 
    612     width = left0->cols;
    613     height = left0->rows;
    614     lofs = MAX(ndisp - 1 + mindisp, 0);
    615     rofs = -MIN(ndisp - 1 + mindisp, 0);
    616     width1 = width - rofs - ndisp + 1;
    617     if( lofs >= width || rofs >= width || width1 < 1 )
    618     {
    619         int FILTERED = (short)((state->minDisparity - 1) << DISPARITY_SHIFT);
    620         cvSet( disp, cvScalarAll(FILTERED) );
    621         EXIT;
    622     }
    623 
    624     wsz = state->SADWindowSize;
    625     bufSize0 = (ndisp + 2)*sizeof(int) + (height+wsz+2)*ndisp*sizeof(int) +
    626         (height + wsz + 2)*sizeof(int) + (height+wsz+2)*ndisp*(wsz+1)*sizeof(uchar) + 256;
    627     bufSize1 = (width + state->preFilterSize + 2)*sizeof(int) + 256;
    628     bufSize = MAX(bufSize0, bufSize1);
    629     n = MAX(MIN(height/wsz, n), 1);
    630 
    631     if( !state->slidingSumBuf || state->slidingSumBuf->cols < bufSize*n )
    632     {
    633         cvReleaseMat( &state->slidingSumBuf );
    634         state->slidingSumBuf = cvCreateMat( 1, bufSize*n, CV_8U );
    635     }
    636 
    637 #ifdef _OPENMP
    638 #pragma omp parallel sections num_threads(n)
    639 #endif
    640     {
    641     #ifdef _OPENMP
    642     #pragma omp section
    643     #endif
    644         icvPrefilter( left0, &left, state->preFilterSize,
    645             state->preFilterCap, state->slidingSumBuf->data.ptr );
    646     #ifdef _OPENMP
    647     #pragma omp section
    648     #endif
    649         icvPrefilter( right0, &right, state->preFilterSize,
    650             state->preFilterCap, state->slidingSumBuf->data.ptr + bufSize1*(n>1) );
    651     }
    652 
    653 #ifdef _OPENMP
    654     #pragma omp parallel for num_threads(n) schedule(static)
    655 #endif
    656     for( i = 0; i < n; i++ )
    657     {
    658         int thread_id = cvGetThreadNum();
    659         CvMat left_i, right_i, disp_i;
    660         int row0 = i*left.rows/n, row1 = (i+1)*left.rows/n;
    661         cvGetRows( &left, &left_i, row0, row1 );
    662         cvGetRows( &right, &right_i, row0, row1 );
    663         cvGetRows( disp, &disp_i, row0, row1 );
    664     #if CV_SSE2
    665         if( state->preFilterCap <= 31 && state->SADWindowSize <= 21 )
    666         {
    667             icvFindStereoCorrespondenceBM_SSE2( &left_i, &right_i, &disp_i, state,
    668                 state->slidingSumBuf->data.ptr + thread_id*bufSize0, row0, left.rows-row1 );
    669         }
    670         else
    671     #endif
    672         {
    673             icvFindStereoCorrespondenceBM( &left_i, &right_i, &disp_i, state,
    674                 state->slidingSumBuf->data.ptr + thread_id*bufSize0, row0, left.rows-row1 );
    675         }
    676     }
    677 
    678     __END__;
    679 }
    680 
    681 /* End of file. */
    682