/*
* call-seq:
* codes -> array(contain fixnum)
*
* Return Freeman chain codes.
*/
VALUE
rb_codes(VALUE self)
{
CvChain *chain = CVCHAIN(self);
CvChainPtReader reader;
int total = chain->total;
VALUE ary = rb_ary_new2(total);
try {
cvStartReadChainPoints(chain, &reader);
for (int i = 0; i < total; ++i) {
CV_READ_SEQ_ELEM(reader.code, (*((CvSeqReader*)&(reader))));
rb_ary_store(ary, i, CHR2FIX(reader.code));
}
}
catch (cv::Exception& e) {
raise_cverror(e);
}
return ary;
}
/*
* call-seq:
* points -> array(contain cvpoint)
*
* Return points that represent by Freeman chain code.
*/
VALUE
rb_points(VALUE self)
{
CvChain *chain = CVCHAIN(self);
CvChainPtReader reader;
CvPoint p = chain->origin;
int total = chain->total;
VALUE ary = rb_ary_new2(total);
try {
cvStartReadChainPoints(chain, &reader);
for (int i = 0; i < total; ++i) {
CV_READ_CHAIN_POINT(p, reader);
rb_ary_store(ary, i, cCvPoint::new_object(p));
}
}
catch (cv::Exception& e) {
raise_cverror(e);
}
return ary;
}
static CvStatus
icvFindDominantPointsIPAN( CvSeq * contour,
CvMemStorage * storage,
CvSeq ** corners, int dmin2, int dmax2, int dneigh2, float amax )
{
CvStatus status = CV_OK;
/* variables */
int n = contour->total;
float *sharpness;
float *distance;
icvPointInfo *ptInf;
int i, j, k;
CvSeqWriter writer;
float mincos = (float) cos( 3.14159265359 * amax / 180 );
/* check bad arguments */
if( contour == NULL )
return CV_NULLPTR_ERR;
if( storage == NULL )
return CV_NULLPTR_ERR;
if( corners == NULL )
return CV_NULLPTR_ERR;
if( dmin2 < 0 )
return CV_BADSIZE_ERR;
if( dmax2 < dmin2 )
return CV_BADSIZE_ERR;
if( (dneigh2 > dmax2) || (dneigh2 < 0) )
return CV_BADSIZE_ERR;
if( (amax < 0) || (amax > 180) )
return CV_BADSIZE_ERR;
sharpness = (float *) cvAlloc( n * sizeof( float ));
distance = (float *) cvAlloc( n * sizeof( float ));
ptInf = (icvPointInfo *) cvAlloc( n * sizeof( icvPointInfo ));
/*****************************************************************************************/
/* First pass */
/*****************************************************************************************/
if( CV_IS_SEQ_CHAIN_CONTOUR( contour ))
{
CvChainPtReader reader;
cvStartReadChainPoints( (CvChain *) contour, &reader );
for( i = 0; i < n; i++ )
{
CV_READ_CHAIN_POINT( ptInf[i].pt, reader );
}
}
else if( CV_IS_SEQ_POLYGON( contour ))
{
CvSeqReader reader;
cvStartReadSeq( contour, &reader, 0 );
for( i = 0; i < n; i++ )
{
CV_READ_SEQ_ELEM( ptInf[i].pt, reader );
}
}
else
{
return CV_BADFLAG_ERR;
}
for( i = 0; i < n; i++ )
{
/* find nearest suitable points
which satisfy distance constraint >dmin */
int left_near = 0;
int right_near = 0;
int left_far, right_far;
float dist_l = 0;
float dist_r = 0;
int i_plus = 0;
int i_minus = 0;
float max_cos_alpha;
/* find right minimum */
while( dist_r < dmin2 )
{
float dx, dy;
int ind;
if( i_plus >= n )
goto error;
right_near = i_plus;
if( dist_r < dneigh2 )
ptInf[i].right_neigh = i_plus;
i_plus++;
ind = (i + i_plus) % n;
dx = (float) (ptInf[i].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[i].pt.y - ptInf[ind].pt.y);
dist_r = dx * dx + dy * dy;
}
/* find right maximum */
while( dist_r <= dmax2 )
{
float dx, dy;
int ind;
if( i_plus >= n )
goto error;
distance[(i + i_plus) % n] = cvSqrt( dist_r );
if( dist_r < dneigh2 )
ptInf[i].right_neigh = i_plus;
i_plus++;
right_far = i_plus;
ind = (i + i_plus) % n;
dx = (float) (ptInf[i].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[i].pt.y - ptInf[ind].pt.y);
dist_r = dx * dx + dy * dy;
}
right_far = i_plus;
/* left minimum */
while( dist_l < dmin2 )
{
float dx, dy;
int ind;
if( i_minus <= -n )
goto error;
left_near = i_minus;
if( dist_l < dneigh2 )
ptInf[i].left_neigh = i_minus;
i_minus--;
ind = i + i_minus;
ind = (ind < 0) ? (n + ind) : ind;
dx = (float) (ptInf[i].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[i].pt.y - ptInf[ind].pt.y);
dist_l = dx * dx + dy * dy;
}
/* find left maximum */
while( dist_l <= dmax2 )
{
float dx, dy;
int ind;
if( i_minus <= -n )
goto error;
ind = i + i_minus;
ind = (ind < 0) ? (n + ind) : ind;
distance[ind] = cvSqrt( dist_l );
if( dist_l < dneigh2 )
ptInf[i].left_neigh = i_minus;
i_minus--;
left_far = i_minus;
ind = i + i_minus;
ind = (ind < 0) ? (n + ind) : ind;
dx = (float) (ptInf[i].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[i].pt.y - ptInf[ind].pt.y);
dist_l = dx * dx + dy * dy;
}
left_far = i_minus;
if( (i_plus - i_minus) > n + 2 )
goto error;
max_cos_alpha = -1;
for( j = left_far + 1; j < left_near; j++ )
{
float dx, dy;
float a, a2;
int leftind = i + j;
leftind = (leftind < 0) ? (n + leftind) : leftind;
a = distance[leftind];
a2 = a * a;
for( k = right_near + 1; k < right_far; k++ )
{
int ind = (i + k) % n;
float c2, cosalpha;
float b = distance[ind];
float b2 = b * b;
/* compute cosinus */
dx = (float) (ptInf[leftind].pt.x - ptInf[ind].pt.x);
dy = (float) (ptInf[leftind].pt.y - ptInf[ind].pt.y);
c2 = dx * dx + dy * dy;
cosalpha = (a2 + b2 - c2) / (2 * a * b);
max_cos_alpha = MAX( max_cos_alpha, cosalpha );
if( max_cos_alpha < mincos )
max_cos_alpha = -1;
sharpness[i] = max_cos_alpha;
}
}
}
/*****************************************************************************************/
/* Second pass */
/*****************************************************************************************/
cvStartWriteSeq( (contour->flags & ~CV_SEQ_ELTYPE_MASK) | CV_SEQ_ELTYPE_INDEX,
sizeof( CvSeq ), sizeof( int ), storage, &writer );
/* second pass - nonmaxima suppression */
/* neighborhood of point < dneigh2 */
for( i = 0; i < n; i++ )
{
int suppressed = 0;
if( sharpness[i] == -1 )
continue;
for( j = 1; (j <= ptInf[i].right_neigh) && (suppressed == 0); j++ )
{
if( sharpness[i] < sharpness[(i + j) % n] )
suppressed = 1;
}
for( j = -1; (j >= ptInf[i].left_neigh) && (suppressed == 0); j-- )
{
int ind = i + j;
ind = (ind < 0) ? (n + ind) : ind;
if( sharpness[i] < sharpness[ind] )
suppressed = 1;
}
if( !suppressed )
CV_WRITE_SEQ_ELEM( i, writer );
}
*corners = cvEndWriteSeq( &writer );
cvFree( &sharpness );
cvFree( &distance );
cvFree( &ptInf );
return status;
error:
/* dmax is so big (more than contour diameter)
that algorithm could become infinite cycle */
cvFree( &sharpness );
cvFree( &distance );
cvFree( &ptInf );
return CV_BADRANGE_ERR;
}