opencv/modules/imgproc/src/hough.cpp
Andrey Kamaev 2a6fb2867e Remove all using directives for STL namespace and members
Made all STL usages explicit to be able automatically find all usages of
particular class or function.
2013-02-25 15:04:17 +04:00

1069 lines
33 KiB
C++

/*M///////////////////////////////////////////////////////////////////////////////////////
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#include "precomp.hpp"
namespace cv
{
// Classical Hough Transform
struct LinePolar
{
float rho;
float angle;
};
struct hough_cmp_gt
{
hough_cmp_gt(const int* _aux) : aux(_aux) {}
bool operator()(int l1, int l2) const { return aux[l1] > aux[l2]; }
const int* aux;
};
/*
Here image is an input raster;
step is it's step; size characterizes it's ROI;
rho and theta are discretization steps (in pixels and radians correspondingly).
threshold is the minimum number of pixels in the feature for it
to be a candidate for line. lines is the output
array of (rho, theta) pairs. linesMax is the buffer size (number of pairs).
Functions return the actual number of found lines.
*/
static void
HoughLinesStandard( const Mat& img, float rho, float theta,
int threshold, std::vector<Vec2f>& lines, int linesMax )
{
int i, j;
float irho = 1 / rho;
CV_Assert( img.type() == CV_8UC1 );
const uchar* image = img.data;
int step = (int)img.step;
int width = img.cols;
int height = img.rows;
int numangle = cvRound(CV_PI / theta);
int numrho = cvRound(((width + height) * 2 + 1) / rho);
AutoBuffer<int> _accum((numangle+2) * (numrho+2));
std::vector<int> _sort_buf;
AutoBuffer<float> _tabSin(numangle);
AutoBuffer<float> _tabCos(numangle);
int *accum = _accum;
float *tabSin = _tabSin, *tabCos = _tabCos;
memset( accum, 0, sizeof(accum[0]) * (numangle+2) * (numrho+2) );
float ang = 0;
for(int n = 0; n < numangle; ang += theta, n++ )
{
tabSin[n] = (float)(sin((double)ang) * irho);
tabCos[n] = (float)(cos((double)ang) * irho);
}
// stage 1. fill accumulator
for( i = 0; i < height; i++ )
for( j = 0; j < width; j++ )
{
if( image[i * step + j] != 0 )
for(int n = 0; n < numangle; n++ )
{
int r = cvRound( j * tabCos[n] + i * tabSin[n] );
r += (numrho - 1) / 2;
accum[(n+1) * (numrho+2) + r+1]++;
}
}
// stage 2. find local maximums
for(int r = 0; r < numrho; r++ )
for(int n = 0; n < numangle; n++ )
{
int base = (n+1) * (numrho+2) + r+1;
if( accum[base] > threshold &&
accum[base] > accum[base - 1] && accum[base] >= accum[base + 1] &&
accum[base] > accum[base - numrho - 2] && accum[base] >= accum[base + numrho + 2] )
_sort_buf.push_back(base);
}
// stage 3. sort the detected lines by accumulator value
cv::sort(_sort_buf, hough_cmp_gt(accum));
// stage 4. store the first min(total,linesMax) lines to the output buffer
linesMax = std::min(linesMax, (int)_sort_buf.size());
double scale = 1./(numrho+2);
for( i = 0; i < linesMax; i++ )
{
LinePolar line;
int idx = _sort_buf[i];
int n = cvFloor(idx*scale) - 1;
int r = idx - (n+1)*(numrho+2) - 1;
line.rho = (r - (numrho - 1)*0.5f) * rho;
line.angle = n * theta;
lines.push_back(Vec2f(line.rho, line.angle));
}
}
// Multi-Scale variant of Classical Hough Transform
struct hough_index
{
hough_index() : value(0), rho(0.f), theta(0.f) {}
hough_index(int _val, float _rho, float _theta)
: value(_val), rho(_rho), theta(_theta) {}
int value;
float rho, theta;
};
static void
HoughLinesSDiv( const Mat& img,
float rho, float theta, int threshold,
int srn, int stn,
std::vector<Vec2f>& lines, int linesMax )
{
#define _POINT(row, column)\
(image_src[(row)*step+(column)])
int index, i;
int ri, ti, ti1, ti0;
int row, col;
float r, t; /* Current rho and theta */
float rv; /* Some temporary rho value */
int fn = 0;
float xc, yc;
const float d2r = (float)(CV_PI / 180);
int sfn = srn * stn;
int fi;
int count;
int cmax = 0;
std::vector<hough_index> lst;
CV_Assert( img.type() == CV_8UC1 );
CV_Assert( linesMax > 0 && rho > 0 && theta > 0 );
threshold = MIN( threshold, 255 );
const uchar* image_src = img.data;
int step = (int)img.step;
int w = img.cols;
int h = img.rows;
float irho = 1 / rho;
float itheta = 1 / theta;
float srho = rho / srn;
float stheta = theta / stn;
float isrho = 1 / srho;
float istheta = 1 / stheta;
int rn = cvFloor( std::sqrt( (double)w * w + (double)h * h ) * irho );
int tn = cvFloor( 2 * CV_PI * itheta );
lst.push_back(hough_index(threshold, -1.f, 0.f));
// Precalculate sin table
std::vector<float> _sinTable( 5 * tn * stn );
float* sinTable = &_sinTable[0];
for( index = 0; index < 5 * tn * stn; index++ )
sinTable[index] = (float)cos( stheta * index * 0.2f );
std::vector<uchar> _caccum(rn * tn, (uchar)0);
uchar* caccum = &_caccum[0];
// Counting all feature pixels
for( row = 0; row < h; row++ )
for( col = 0; col < w; col++ )
fn += _POINT( row, col ) != 0;
std::vector<int> _x(fn), _y(fn);
int* x = &_x[0], *y = &_y[0];
// Full Hough Transform (it's accumulator update part)
fi = 0;
for( row = 0; row < h; row++ )
{
for( col = 0; col < w; col++ )
{
if( _POINT( row, col ))
{
int halftn;
float r0;
float scale_factor;
int iprev = -1;
float phi, phi1;
float theta_it; // Value of theta for iterating
// Remember the feature point
x[fi] = col;
y[fi] = row;
fi++;
yc = (float) row + 0.5f;
xc = (float) col + 0.5f;
/* Update the accumulator */
t = (float) fabs( cvFastArctan( yc, xc ) * d2r );
r = (float) std::sqrt( (double)xc * xc + (double)yc * yc );
r0 = r * irho;
ti0 = cvFloor( (t + CV_PI*0.5) * itheta );
caccum[ti0]++;
theta_it = rho / r;
theta_it = theta_it < theta ? theta_it : theta;
scale_factor = theta_it * itheta;
halftn = cvFloor( CV_PI / theta_it );
for( ti1 = 1, phi = theta_it - (float)(CV_PI*0.5), phi1 = (theta_it + t) * itheta;
ti1 < halftn; ti1++, phi += theta_it, phi1 += scale_factor )
{
rv = r0 * std::cos( phi );
i = cvFloor( rv ) * tn;
i += cvFloor( phi1 );
assert( i >= 0 );
assert( i < rn * tn );
caccum[i] = (uchar) (caccum[i] + ((i ^ iprev) != 0));
iprev = i;
if( cmax < caccum[i] )
cmax = caccum[i];
}
}
}
}
// Starting additional analysis
count = 0;
for( ri = 0; ri < rn; ri++ )
{
for( ti = 0; ti < tn; ti++ )
{
if( caccum[ri * tn + ti] > threshold )
count++;
}
}
if( count * 100 > rn * tn )
{
HoughLinesStandard( img, rho, theta, threshold, lines, linesMax );
return;
}
std::vector<uchar> _buffer(srn * stn + 2);
uchar* buffer = &_buffer[0];
uchar* mcaccum = buffer + 1;
count = 0;
for( ri = 0; ri < rn; ri++ )
{
for( ti = 0; ti < tn; ti++ )
{
if( caccum[ri * tn + ti] > threshold )
{
count++;
memset( mcaccum, 0, sfn * sizeof( uchar ));
for( index = 0; index < fn; index++ )
{
int ti2;
float r0;
yc = (float) y[index] + 0.5f;
xc = (float) x[index] + 0.5f;
// Update the accumulator
t = (float) fabs( cvFastArctan( yc, xc ) * d2r );
r = (float) std::sqrt( (double)xc * xc + (double)yc * yc ) * isrho;
ti0 = cvFloor( (t + CV_PI * 0.5) * istheta );
ti2 = (ti * stn - ti0) * 5;
r0 = (float) ri *srn;
for( ti1 = 0; ti1 < stn; ti1++, ti2 += 5 )
{
rv = r * sinTable[(int) (std::abs( ti2 ))] - r0;
i = cvFloor( rv ) * stn + ti1;
i = CV_IMAX( i, -1 );
i = CV_IMIN( i, sfn );
mcaccum[i]++;
assert( i >= -1 );
assert( i <= sfn );
}
}
// Find peaks in maccum...
for( index = 0; index < sfn; index++ )
{
i = 0;
int pos = (int)(lst.size() - 1);
if( pos < 0 || lst[pos].value < mcaccum[index] )
{
hough_index vi(mcaccum[index],
index / stn * srho + ri * rho,
index % stn * stheta + ti * theta - (float)(CV_PI*0.5));
lst.push_back(vi);
for( ; pos >= 0; pos-- )
{
if( lst[pos].value > vi.value )
break;
lst[pos+1] = lst[pos];
}
lst[pos+1] = vi;
if( (int)lst.size() > linesMax )
lst.pop_back();
}
}
}
}
}
for( size_t idx = 0; idx < lst.size(); idx++ )
{
if( lst[idx].rho < 0 )
continue;
lines.push_back(Vec2f(lst[idx].rho, lst[idx].theta));
}
}
/****************************************************************************************\
* Probabilistic Hough Transform *
\****************************************************************************************/
static void
HoughLinesProbabilistic( Mat& image,
float rho, float theta, int threshold,
int lineLength, int lineGap,
std::vector<Vec4i>& lines, int linesMax )
{
Point pt;
float irho = 1 / rho;
RNG rng((uint64)-1);
CV_Assert( image.type() == CV_8UC1 );
int width = image.cols;
int height = image.rows;
int numangle = cvRound(CV_PI / theta);
int numrho = cvRound(((width + height) * 2 + 1) / rho);
Mat accum = Mat::zeros( numangle, numrho, CV_32SC1 );
Mat mask( height, width, CV_8UC1 );
std::vector<float> trigtab(numangle*2);
for( int n = 0; n < numangle; n++ )
{
trigtab[n*2] = (float)(cos((double)n*theta) * irho);
trigtab[n*2+1] = (float)(sin((double)n*theta) * irho);
}
const float* ttab = &trigtab[0];
uchar* mdata0 = mask.data;
std::vector<Point> nzloc;
// stage 1. collect non-zero image points
for( pt.y = 0; pt.y < height; pt.y++ )
{
const uchar* data = image.ptr(pt.y);
uchar* mdata = mask.ptr(pt.y);
for( pt.x = 0; pt.x < width; pt.x++ )
{
if( data[pt.x] )
{
mdata[pt.x] = (uchar)1;
nzloc.push_back(pt);
}
else
mdata[pt.x] = 0;
}
}
int count = (int)nzloc.size();
// stage 2. process all the points in random order
for( ; count > 0; count-- )
{
// choose random point out of the remaining ones
int idx = rng.uniform(0, count);
int max_val = threshold-1, max_n = 0;
Point point = nzloc[idx];
Point line_end[2];
float a, b;
int* adata = (int*)accum.data;
int i = point.y, j = point.x, k, x0, y0, dx0, dy0, xflag;
int good_line;
const int shift = 16;
// "remove" it by overriding it with the last element
nzloc[idx] = nzloc[count-1];
// check if it has been excluded already (i.e. belongs to some other line)
if( !mdata0[i*width + j] )
continue;
// update accumulator, find the most probable line
for( int n = 0; n < numangle; n++, adata += numrho )
{
int r = cvRound( j * ttab[n*2] + i * ttab[n*2+1] );
r += (numrho - 1) / 2;
int val = ++adata[r];
if( max_val < val )
{
max_val = val;
max_n = n;
}
}
// if it is too "weak" candidate, continue with another point
if( max_val < threshold )
continue;
// from the current point walk in each direction
// along the found line and extract the line segment
a = -ttab[max_n*2+1];
b = ttab[max_n*2];
x0 = j;
y0 = i;
if( fabs(a) > fabs(b) )
{
xflag = 1;
dx0 = a > 0 ? 1 : -1;
dy0 = cvRound( b*(1 << shift)/fabs(a) );
y0 = (y0 << shift) + (1 << (shift-1));
}
else
{
xflag = 0;
dy0 = b > 0 ? 1 : -1;
dx0 = cvRound( a*(1 << shift)/fabs(b) );
x0 = (x0 << shift) + (1 << (shift-1));
}
for( k = 0; k < 2; k++ )
{
int gap = 0, x = x0, y = y0, dx = dx0, dy = dy0;
if( k > 0 )
dx = -dx, dy = -dy;
// walk along the line using fixed-point arithmetics,
// stop at the image border or in case of too big gap
for( ;; x += dx, y += dy )
{
uchar* mdata;
int i1, j1;
if( xflag )
{
j1 = x;
i1 = y >> shift;
}
else
{
j1 = x >> shift;
i1 = y;
}
if( j1 < 0 || j1 >= width || i1 < 0 || i1 >= height )
break;
mdata = mdata0 + i1*width + j1;
// for each non-zero point:
// update line end,
// clear the mask element
// reset the gap
if( *mdata )
{
gap = 0;
line_end[k].y = i1;
line_end[k].x = j1;
}
else if( ++gap > lineGap )
break;
}
}
good_line = std::abs(line_end[1].x - line_end[0].x) >= lineLength ||
std::abs(line_end[1].y - line_end[0].y) >= lineLength;
for( k = 0; k < 2; k++ )
{
int x = x0, y = y0, dx = dx0, dy = dy0;
if( k > 0 )
dx = -dx, dy = -dy;
// walk along the line using fixed-point arithmetics,
// stop at the image border or in case of too big gap
for( ;; x += dx, y += dy )
{
uchar* mdata;
int i1, j1;
if( xflag )
{
j1 = x;
i1 = y >> shift;
}
else
{
j1 = x >> shift;
i1 = y;
}
mdata = mdata0 + i1*width + j1;
// for each non-zero point:
// update line end,
// clear the mask element
// reset the gap
if( *mdata )
{
if( good_line )
{
adata = (int*)accum.data;
for( int n = 0; n < numangle; n++, adata += numrho )
{
int r = cvRound( j1 * ttab[n*2] + i1 * ttab[n*2+1] );
r += (numrho - 1) / 2;
adata[r]--;
}
}
*mdata = 0;
}
if( i1 == line_end[k].y && j1 == line_end[k].x )
break;
}
}
if( good_line )
{
Vec4i lr(line_end[0].x, line_end[0].y, line_end[1].x, line_end[1].y);
lines.push_back(lr);
if( (int)lines.size() >= linesMax )
return;
}
}
}
}
void cv::HoughLines( InputArray _image, OutputArray _lines,
double rho, double theta, int threshold,
double srn, double stn )
{
Mat image = _image.getMat();
std::vector<Vec2f> lines;
if( srn == 0 && stn == 0 )
HoughLinesStandard(image, (float)rho, (float)theta, threshold, lines, INT_MAX);
else
HoughLinesSDiv(image, (float)rho, (float)theta, threshold, cvRound(srn), cvRound(stn), lines, INT_MAX);
Mat(lines).copyTo(_lines);
}
void cv::HoughLinesP(InputArray _image, OutputArray _lines,
double rho, double theta, int threshold,
double minLineLength, double maxGap )
{
Mat image = _image.getMat();
std::vector<Vec4i> lines;
HoughLinesProbabilistic(image, (float)rho, (float)theta, threshold, cvRound(minLineLength), cvRound(maxGap), lines, INT_MAX);
Mat(lines).copyTo(_lines);
}
/* Wrapper function for standard hough transform */
CV_IMPL CvSeq*
cvHoughLines2( CvArr* src_image, void* lineStorage, int method,
double rho, double theta, int threshold,
double param1, double param2 )
{
cv::Mat image = cv::cvarrToMat(src_image);
std::vector<cv::Vec2f> l2;
std::vector<cv::Vec4i> l4;
CvSeq* result = 0;
CvMat* mat = 0;
CvSeq* lines = 0;
CvSeq lines_header;
CvSeqBlock lines_block;
int lineType, elemSize;
int linesMax = INT_MAX;
int iparam1, iparam2;
if( !lineStorage )
CV_Error( CV_StsNullPtr, "NULL destination" );
if( rho <= 0 || theta <= 0 || threshold <= 0 )
CV_Error( CV_StsOutOfRange, "rho, theta and threshold must be positive" );
if( method != CV_HOUGH_PROBABILISTIC )
{
lineType = CV_32FC2;
elemSize = sizeof(float)*2;
}
else
{
lineType = CV_32SC4;
elemSize = sizeof(int)*4;
}
if( CV_IS_STORAGE( lineStorage ))
{
lines = cvCreateSeq( lineType, sizeof(CvSeq), elemSize, (CvMemStorage*)lineStorage );
}
else if( CV_IS_MAT( lineStorage ))
{
mat = (CvMat*)lineStorage;
if( !CV_IS_MAT_CONT( mat->type ) || (mat->rows != 1 && mat->cols != 1) )
CV_Error( CV_StsBadArg,
"The destination matrix should be continuous and have a single row or a single column" );
if( CV_MAT_TYPE( mat->type ) != lineType )
CV_Error( CV_StsBadArg,
"The destination matrix data type is inappropriate, see the manual" );
lines = cvMakeSeqHeaderForArray( lineType, sizeof(CvSeq), elemSize, mat->data.ptr,
mat->rows + mat->cols - 1, &lines_header, &lines_block );
linesMax = lines->total;
cvClearSeq( lines );
}
else
CV_Error( CV_StsBadArg, "Destination is not CvMemStorage* nor CvMat*" );
iparam1 = cvRound(param1);
iparam2 = cvRound(param2);
switch( method )
{
case CV_HOUGH_STANDARD:
HoughLinesStandard( image, (float)rho,
(float)theta, threshold, l2, linesMax );
break;
case CV_HOUGH_MULTI_SCALE:
HoughLinesSDiv( image, (float)rho, (float)theta,
threshold, iparam1, iparam2, l2, linesMax );
break;
case CV_HOUGH_PROBABILISTIC:
HoughLinesProbabilistic( image, (float)rho, (float)theta,
threshold, iparam1, iparam2, l4, linesMax );
break;
default:
CV_Error( CV_StsBadArg, "Unrecognized method id" );
}
int nlines = (int)(l2.size() + l4.size());
if( mat )
{
if( mat->cols > mat->rows )
mat->cols = nlines;
else
mat->rows = nlines;
}
if( nlines )
{
cv::Mat lx = method == CV_HOUGH_STANDARD || method == CV_HOUGH_MULTI_SCALE ?
cv::Mat(nlines, 1, CV_32FC2, &l2[0]) : cv::Mat(nlines, 1, CV_32SC4, &l4[0]);
if( mat )
{
cv::Mat dst(nlines, 1, lx.type(), mat->data.ptr);
lx.copyTo(dst);
}
else
{
cvSeqPushMulti(lines, lx.data, nlines);
}
}
if( !mat )
result = lines;
return result;
}
/****************************************************************************************\
* Circle Detection *
\****************************************************************************************/
static void
icvHoughCirclesGradient( CvMat* img, float dp, float min_dist,
int min_radius, int max_radius,
int canny_threshold, int acc_threshold,
CvSeq* circles, int circles_max )
{
const int SHIFT = 10, ONE = 1 << SHIFT;
cv::Ptr<CvMat> dx, dy;
cv::Ptr<CvMat> edges, accum, dist_buf;
std::vector<int> sort_buf;
cv::Ptr<CvMemStorage> storage;
int x, y, i, j, k, center_count, nz_count;
float min_radius2 = (float)min_radius*min_radius;
float max_radius2 = (float)max_radius*max_radius;
int rows, cols, arows, acols;
int astep, *adata;
float* ddata;
CvSeq *nz, *centers;
float idp, dr;
CvSeqReader reader;
edges = cvCreateMat( img->rows, img->cols, CV_8UC1 );
cvCanny( img, edges, MAX(canny_threshold/2,1), canny_threshold, 3 );
dx = cvCreateMat( img->rows, img->cols, CV_16SC1 );
dy = cvCreateMat( img->rows, img->cols, CV_16SC1 );
cvSobel( img, dx, 1, 0, 3 );
cvSobel( img, dy, 0, 1, 3 );
if( dp < 1.f )
dp = 1.f;
idp = 1.f/dp;
accum = cvCreateMat( cvCeil(img->rows*idp)+2, cvCeil(img->cols*idp)+2, CV_32SC1 );
cvZero(accum);
storage = cvCreateMemStorage();
nz = cvCreateSeq( CV_32SC2, sizeof(CvSeq), sizeof(CvPoint), storage );
centers = cvCreateSeq( CV_32SC1, sizeof(CvSeq), sizeof(int), storage );
rows = img->rows;
cols = img->cols;
arows = accum->rows - 2;
acols = accum->cols - 2;
adata = accum->data.i;
astep = accum->step/sizeof(adata[0]);
// Accumulate circle evidence for each edge pixel
for( y = 0; y < rows; y++ )
{
const uchar* edges_row = edges->data.ptr + y*edges->step;
const short* dx_row = (const short*)(dx->data.ptr + y*dx->step);
const short* dy_row = (const short*)(dy->data.ptr + y*dy->step);
for( x = 0; x < cols; x++ )
{
float vx, vy;
int sx, sy, x0, y0, x1, y1, r;
CvPoint pt;
vx = dx_row[x];
vy = dy_row[x];
if( !edges_row[x] || (vx == 0 && vy == 0) )
continue;
float mag = std::sqrt(vx*vx+vy*vy);
assert( mag >= 1 );
sx = cvRound((vx*idp)*ONE/mag);
sy = cvRound((vy*idp)*ONE/mag);
x0 = cvRound((x*idp)*ONE);
y0 = cvRound((y*idp)*ONE);
// Step from min_radius to max_radius in both directions of the gradient
for(int k1 = 0; k1 < 2; k1++ )
{
x1 = x0 + min_radius * sx;
y1 = y0 + min_radius * sy;
for( r = min_radius; r <= max_radius; x1 += sx, y1 += sy, r++ )
{
int x2 = x1 >> SHIFT, y2 = y1 >> SHIFT;
if( (unsigned)x2 >= (unsigned)acols ||
(unsigned)y2 >= (unsigned)arows )
break;
adata[y2*astep + x2]++;
}
sx = -sx; sy = -sy;
}
pt.x = x; pt.y = y;
cvSeqPush( nz, &pt );
}
}
nz_count = nz->total;
if( !nz_count )
return;
//Find possible circle centers
for( y = 1; y < arows - 1; y++ )
{
for( x = 1; x < acols - 1; x++ )
{
int base = y*(acols+2) + x;
if( adata[base] > acc_threshold &&
adata[base] > adata[base-1] && adata[base] > adata[base+1] &&
adata[base] > adata[base-acols-2] && adata[base] > adata[base+acols+2] )
cvSeqPush(centers, &base);
}
}
center_count = centers->total;
if( !center_count )
return;
sort_buf.resize( MAX(center_count,nz_count) );
cvCvtSeqToArray( centers, &sort_buf[0] );
std::sort(sort_buf.begin(), sort_buf.begin() + center_count, cv::hough_cmp_gt(adata));
cvClearSeq( centers );
cvSeqPushMulti( centers, &sort_buf[0], center_count );
dist_buf = cvCreateMat( 1, nz_count, CV_32FC1 );
ddata = dist_buf->data.fl;
dr = dp;
min_dist = MAX( min_dist, dp );
min_dist *= min_dist;
// For each found possible center
// Estimate radius and check support
for( i = 0; i < centers->total; i++ )
{
int ofs = *(int*)cvGetSeqElem( centers, i );
y = ofs/(acols+2);
x = ofs - (y)*(acols+2);
//Calculate circle's center in pixels
float cx = (float)((x + 0.5f)*dp), cy = (float)(( y + 0.5f )*dp);
float start_dist, dist_sum;
float r_best = 0;
int max_count = 0;
// Check distance with previously detected circles
for( j = 0; j < circles->total; j++ )
{
float* c = (float*)cvGetSeqElem( circles, j );
if( (c[0] - cx)*(c[0] - cx) + (c[1] - cy)*(c[1] - cy) < min_dist )
break;
}
if( j < circles->total )
continue;
// Estimate best radius
cvStartReadSeq( nz, &reader );
for( j = k = 0; j < nz_count; j++ )
{
CvPoint pt;
float _dx, _dy, _r2;
CV_READ_SEQ_ELEM( pt, reader );
_dx = cx - pt.x; _dy = cy - pt.y;
_r2 = _dx*_dx + _dy*_dy;
if(min_radius2 <= _r2 && _r2 <= max_radius2 )
{
ddata[k] = _r2;
sort_buf[k] = k;
k++;
}
}
int nz_count1 = k, start_idx = nz_count1 - 1;
if( nz_count1 == 0 )
continue;
dist_buf->cols = nz_count1;
cvPow( dist_buf, dist_buf, 0.5 );
std::sort(sort_buf.begin(), sort_buf.begin() + nz_count1, cv::hough_cmp_gt((int*)ddata));
dist_sum = start_dist = ddata[sort_buf[nz_count1-1]];
for( j = nz_count1 - 2; j >= 0; j-- )
{
float d = ddata[sort_buf[j]];
if( d > max_radius )
break;
if( d - start_dist > dr )
{
float r_cur = ddata[sort_buf[(j + start_idx)/2]];
if( (start_idx - j)*r_best >= max_count*r_cur ||
(r_best < FLT_EPSILON && start_idx - j >= max_count) )
{
r_best = r_cur;
max_count = start_idx - j;
}
start_dist = d;
start_idx = j;
dist_sum = 0;
}
dist_sum += d;
}
// Check if the circle has enough support
if( max_count > acc_threshold )
{
float c[3];
c[0] = cx;
c[1] = cy;
c[2] = (float)r_best;
cvSeqPush( circles, c );
if( circles->total > circles_max )
return;
}
}
}
CV_IMPL CvSeq*
cvHoughCircles( CvArr* src_image, void* circle_storage,
int method, double dp, double min_dist,
double param1, double param2,
int min_radius, int max_radius )
{
CvSeq* result = 0;
CvMat stub, *img = (CvMat*)src_image;
CvMat* mat = 0;
CvSeq* circles = 0;
CvSeq circles_header;
CvSeqBlock circles_block;
int circles_max = INT_MAX;
int canny_threshold = cvRound(param1);
int acc_threshold = cvRound(param2);
img = cvGetMat( img, &stub );
if( !CV_IS_MASK_ARR(img))
CV_Error( CV_StsBadArg, "The source image must be 8-bit, single-channel" );
if( !circle_storage )
CV_Error( CV_StsNullPtr, "NULL destination" );
if( dp <= 0 || min_dist <= 0 || canny_threshold <= 0 || acc_threshold <= 0 )
CV_Error( CV_StsOutOfRange, "dp, min_dist, canny_threshold and acc_threshold must be all positive numbers" );
min_radius = MAX( min_radius, 0 );
if( max_radius <= 0 )
max_radius = MAX( img->rows, img->cols );
else if( max_radius <= min_radius )
max_radius = min_radius + 2;
if( CV_IS_STORAGE( circle_storage ))
{
circles = cvCreateSeq( CV_32FC3, sizeof(CvSeq),
sizeof(float)*3, (CvMemStorage*)circle_storage );
}
else if( CV_IS_MAT( circle_storage ))
{
mat = (CvMat*)circle_storage;
if( !CV_IS_MAT_CONT( mat->type ) || (mat->rows != 1 && mat->cols != 1) ||
CV_MAT_TYPE(mat->type) != CV_32FC3 )
CV_Error( CV_StsBadArg,
"The destination matrix should be continuous and have a single row or a single column" );
circles = cvMakeSeqHeaderForArray( CV_32FC3, sizeof(CvSeq), sizeof(float)*3,
mat->data.ptr, mat->rows + mat->cols - 1, &circles_header, &circles_block );
circles_max = circles->total;
cvClearSeq( circles );
}
else
CV_Error( CV_StsBadArg, "Destination is not CvMemStorage* nor CvMat*" );
switch( method )
{
case CV_HOUGH_GRADIENT:
icvHoughCirclesGradient( img, (float)dp, (float)min_dist,
min_radius, max_radius, canny_threshold,
acc_threshold, circles, circles_max );
break;
default:
CV_Error( CV_StsBadArg, "Unrecognized method id" );
}
if( mat )
{
if( mat->cols > mat->rows )
mat->cols = circles->total;
else
mat->rows = circles->total;
}
else
result = circles;
return result;
}
namespace cv
{
const int STORAGE_SIZE = 1 << 12;
static void seqToMat(const CvSeq* seq, OutputArray _arr)
{
if( seq && seq->total > 0 )
{
_arr.create(1, seq->total, seq->flags, -1, true);
Mat arr = _arr.getMat();
cvCvtSeqToArray(seq, arr.data);
}
else
_arr.release();
}
}
void cv::HoughCircles( InputArray _image, OutputArray _circles,
int method, double dp, double min_dist,
double param1, double param2,
int minRadius, int maxRadius )
{
Ptr<CvMemStorage> storage = cvCreateMemStorage(STORAGE_SIZE);
Mat image = _image.getMat();
CvMat c_image = image;
CvSeq* seq = cvHoughCircles( &c_image, storage, method,
dp, min_dist, param1, param2, minRadius, maxRadius );
seqToMat(seq, _circles);
}
/* End of file. */