// default <malloc>
CV_IMPL void* icvDefaultAlloc( size_t size, const char*, int)
{
char *ptr, *ptr0 = (char*)malloc(
(size_t)(size + CV_MALLOC_ALIGN*((size >= 4096) + 1) + sizeof(char*)*2));
if( !ptr0 )
return 0;
// align the pointer
ptr = ptr0 + sizeof(char*)*2 + 1;
ptr = (char*)icvAlignPtr(ptr, CV_MALLOC_ALIGN);
*(char**)(ptr - sizeof(char*)) = ptr0;
return ptr;
}
/*F///////////////////////////////////////////////////////////////////////////////////////
// Name: icvCalcPGH
// Purpose:
// Calculates PGH(pairwise geometric histogram) for contour given.
// Context:
// Parameters:
// contour - pointer to input contour object.
// pgh - output histogram
// ang_dim - number of angle bins (vertical size of histogram)
// dist_dim - number of distance bins (horizontal size of histogram)
// Returns:
// CV_OK or error code
// Notes:
//F*/
CvStatus
icvCalcPGH( CvSeq * contour, float *pgh, int angle_dim, int dist_dim )
{
char local_buffer[(1 << 14) + 32];
float *local_buffer_ptr = (float *)icvAlignPtr(local_buffer,32);
float *buffer = local_buffer_ptr;
double angle_scale = (angle_dim - 0.51) / icv_acos_table[0];
double dist_scale = DBL_EPSILON;
int buffer_size;
int i, count, pass;
int *pghi = (int *) pgh;
int hist_size = angle_dim * dist_dim;
CvSeqReader reader1, reader2; /* external and internal readers */
if( !contour || !pgh )
return CV_NULLPTR_ERR;
if( angle_dim <= 0 || angle_dim > 180 || dist_dim <= 0 )
return CV_BADRANGE_ERR;
if( !CV_IS_SEQ_POLYGON( contour ))
return CV_BADFLAG_ERR;
memset( pgh, 0, hist_size * sizeof( pgh[0] ));
count = contour->total;
/* allocate buffer for distances */
buffer_size = count * sizeof( float );
if( buffer_size > (int)sizeof(local_buffer) - 32 )
{
buffer = (float *) icvAlloc( buffer_size );
if( !buffer )
return CV_OUTOFMEM_ERR;
}
cvStartReadSeq( contour, &reader1, 0 );
cvStartReadSeq( contour, &reader2, 0 );
/* calc & store squared edge lengths, calculate maximal distance between edges */
for( i = 0; i < count; i++ )
{
CvPoint pt1, pt2;
int dx, dy;
CV_READ_EDGE( pt1, pt2, reader1 );
dx = pt2.x - pt1.x;
dy = pt2.y - pt1.y;
buffer[i] = (float) (dx * dx + dy * dy);
}
icvbInvSqrt_32f( buffer, buffer, i );
/*
do 2 passes.
First calculates maximal distance.
Second calculates histogram itself.
*/
for( pass = 1; pass <= 2; pass++ )
{
double dist_coeff = 0, angle_coeff = 0;
/* run external loop */
for( i = 0; i < count; i++ )
{
CvPoint pt1, pt2;
int dx, dy;
int dist = 0;
CV_READ_EDGE( pt1, pt2, reader1 );
dx = pt2.x - pt1.x;
dy = pt2.y - pt1.y;
if( (dx | dy) != 0 )
{
int j;
if( pass == 2 )
{
dist_coeff = buffer[i] * dist_scale;
angle_coeff = buffer[i] * (_CV_ACOS_TABLE_SIZE / 2);
}
/* run internal loop (for current edge) */
for( j = 0; j < count; j++ )
{
CvPoint pt3, pt4;
CV_READ_EDGE( pt3, pt4, reader2 );
if( i != j ) /* process edge pair */
{
int d1 = (pt3.y - pt1.y) * dx - (pt3.x - pt1.x) * dy;
int d2 = (pt4.y - pt1.y) * dx - (pt2.x - pt1.x) * dy;
int cross_flag;
int *hist_row = 0;
if( pass == 2 )
{
int dp = (pt4.x - pt3.x) * dx + (pt4.y - pt3.y) * dy;
dp = cvRound( dp * angle_coeff * buffer[j] ) +
(_CV_ACOS_TABLE_SIZE / 2);
dp = MAX( dp, 0 );
dp = MIN( dp, _CV_ACOS_TABLE_SIZE - 1 );
hist_row = pghi + dist_dim *
cvRound( icv_acos_table[dp] * angle_scale );
d1 = cvRound( d1 * dist_coeff );
d2 = cvRound( d2 * dist_coeff );
}
cross_flag = (d1 ^ d2) < 0;
d1 = CV_IABS( d1 );
d2 = CV_IABS( d2 );
if( pass == 2 )
{
if( d1 >= dist_dim )
d1 = dist_dim - 1;
if( d2 >= dist_dim )
d2 = dist_dim - 1;
if( !cross_flag )
{
if( d1 > d2 ) /* make d1 <= d2 */
{
d1 ^= d2;
d2 ^= d1;
d1 ^= d2;
}
for( ; d1 <= d2; d1++ )
hist_row[d1]++;
}
else
{
for( ; d1 >= 0; d1-- )
hist_row[d1]++;
for( ; d2 >= 0; d2-- )
hist_row[d2]++;
}
}
else /* 1st pass */
{
d1 = CV_IMAX( d1, d2 );
dist = CV_IMAX( dist, d1 );
}
} /* end of processing of edge pair */
} /* end of internal loop */
if( pass == 1 )
{
double scale = dist * buffer[i];
dist_scale = MAX( dist_scale, scale );
}
}
} /* end of external loop */
if( pass == 1 )
{
dist_scale = (dist_dim - 0.51) / dist_scale;
}
} /* end of pass on loops */
/* convert hist to floats */
for( i = 0; i < hist_size; i++ )
{
((float *) pghi)[i] = (float) pghi[i];
}
if( buffer != local_buffer_ptr )
icvFree( &buffer );
return CV_OK;
}
