/modules/imgproc/src/hough.cpp
C++ | 1080 lines | 818 code | 160 blank | 102 comment | 169 complexity | 0d4c22fab3e10d092931bde58bbca1b8 MD5 | raw file
Possible License(s): BSD-3-Clause, LGPL-3.0
- /*M///////////////////////////////////////////////////////////////////////////////////////
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- //M*/
- #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] || (aux[l1] == aux[l2] && l1 < 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,
- double min_theta, double max_theta )
- {
- 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;
- if (max_theta < 0 || max_theta > CV_PI ) {
- CV_Error( CV_StsBadArg, "max_theta must fall between 0 and pi" );
- }
- if (min_theta < 0 || min_theta > max_theta ) {
- CV_Error( CV_StsBadArg, "min_theta must fall between 0 and max_theta" );
- }
- int numangle = cvRound((max_theta - min_theta) / 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 = static_cast<float>(min_theta);
- 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
- std::sort(_sort_buf.begin(), _sort_buf.end(), 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,
- double min_theta, double max_theta )
- {
- #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, min_theta, max_theta );
- 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, double min_theta, double max_theta )
- {
- Mat image = _image.getMat();
- std::vector<Vec2f> lines;
- if( srn == 0 && stn == 0 )
- HoughLinesStandard(image, (float)rho, (float)theta, threshold, lines, INT_MAX, min_theta, max_theta );
- else
- HoughLinesSDiv(image, (float)rho, (float)theta, threshold, cvRound(srn), cvRound(stn), lines, INT_MAX, min_theta, max_theta);
- 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,
- double min_theta, double max_theta )
- {
- 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, min_theta, max_theta );
- break;
- case CV_HOUGH_MULTI_SCALE:
- HoughLinesSDiv( image, (float)rho, (float)theta,
- threshold, iparam1, iparam2, l2, linesMax, min_theta, max_theta );
- 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.reset(cvCreateMat( img->rows, img->cols, CV_8UC1 ));
- cvCanny( img, edges, MAX(canny_threshold/2,1), canny_threshold, 3 );
- dx.reset(cvCreateMat( img->rows, img->cols, CV_16SC1 ));
- dy.reset(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.reset(cvCreateMat( cvCeil(img->rows*idp)+2, cvCeil(img->cols*idp)+2, CV_32SC1 ));
- cvZero(accum);
- storage.reset(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.reset(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. */