/*M/////////////////////////////////////////////////////////////////////////////////////// // // IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING. // // By downloading, copying, installing or using the software you agree to this license. // If you do not agree to this license, do not download, install, // copy or use the software. // // // Intel License Agreement // For Open Source Computer Vision Library // // Copyright (C) 2000, Intel Corporation, all rights reserved. // Third party copyrights are property of their respective owners. // // Redistribution and use in source and binary forms, with or without modification, // are permitted provided that the following conditions are met: // // * Redistribution's of source code must retain the above copyright notice, // this list of conditions and the following disclaimer. // // * Redistribution's in binary form must reproduce the above copyright notice, // this list of conditions and the following disclaimer in the documentation // and/or other materials provided with the distribution. // // * The name of Intel Corporation may not be used to endorse or promote products // derived from this software without specific prior written permission. // // This software is provided by the copyright holders and contributors "as is" and // any express or implied warranties, including, but not limited to, the implied // warranties of merchantability and fitness for a particular purpose are disclaimed. // In no event shall the Intel Corporation or contributors be liable for any direct, // indirect, incidental, special, exemplary, or consequential damages // (including, but not limited to, procurement of substitute goods or services; // loss of use, data, or profits; or business interruption) however caused // and on any theory of liability, whether in contract, strict liability, // or tort (including negligence or otherwise) arising in any way out of // the use of this software, even if advised of the possibility of such damage. // //M*/ #include "precomp.hpp" #include #include namespace cv { template struct greaterThanPtr { bool operator()(const T* a, const T* b) const { return *a > *b; } }; void goodFeaturesToTrack( const Mat& image, vector& corners, int maxCorners, double qualityLevel, double minDistance, const Mat& mask, int blockSize, bool useHarrisDetector, double harrisK ) { CV_Assert( qualityLevel > 0 && minDistance >= 0 && maxCorners >= 0 ); CV_Assert( mask.empty() || (mask.type() == CV_8UC1 && mask.size() == image.size()) ); Mat eig, tmp; if( useHarrisDetector ) cornerHarris( image, eig, blockSize, 3, harrisK ); else cornerMinEigenVal( image, eig, blockSize, 3 ); double maxVal = 0; minMaxLoc( eig, 0, &maxVal, 0, 0, mask ); threshold( eig, eig, maxVal*qualityLevel, 0, THRESH_TOZERO ); dilate( eig, tmp, Mat()); Size imgsize = image.size(); vector tmpCorners; // collect list of pointers to features - put them into temporary image for( int y = 1; y < imgsize.height - 1; y++ ) { const float* eig_data = (const float*)eig.ptr(y); const float* tmp_data = (const float*)tmp.ptr(y); const uchar* mask_data = mask.data ? mask.ptr(y) : 0; for( int x = 1; x < imgsize.width - 1; x++ ) { float val = eig_data[x]; if( val != 0 && val == tmp_data[x] && (!mask_data || mask_data[x]) ) tmpCorners.push_back(eig_data + x); } } sort( tmpCorners, greaterThanPtr() ); corners.clear(); size_t i, j, total = tmpCorners.size(), ncorners = 0; if(minDistance >= 1) { // Partition the image into larger grids int w = image.cols; int h = image.rows; const int cell_size = cvRound(minDistance); const int grid_width = (w + cell_size - 1) / cell_size; const int grid_height = (h + cell_size - 1) / cell_size; std::vector > grid(grid_width*grid_height); minDistance *= minDistance; for( i = 0; i < total; i++ ) { int ofs = (int)((const uchar*)tmpCorners[i] - eig.data); int y = (int)(ofs / eig.step); int x = (int)((ofs - y*eig.step)/sizeof(float)); bool good = true; int x_cell = x / cell_size; int y_cell = y / cell_size; int x1 = x_cell - 1; int y1 = y_cell - 1; int x2 = x_cell + 1; int y2 = y_cell + 1; // boundary check x1 = std::max(0, x1); y1 = std::max(0, y1); x2 = std::min(grid_width-1, x2); y2 = std::min(grid_height-1, y2); for( int yy = y1; yy <= y2; yy++ ) { for( int xx = x1; xx <= x2; xx++ ) { vector &m = grid[yy*grid_width + xx]; if( m.size() ) { for(j = 0; j < m.size(); j++) { float dx = x - m[j].x; float dy = y - m[j].y; if( dx*dx + dy*dy < minDistance ) { good = false; goto break_out; } } } } } break_out: if(good) { // printf("%d: %d %d -> %d %d, %d, %d -- %d %d %d %d, %d %d, c=%d\n", // i,x, y, x_cell, y_cell, (int)minDistance, cell_size,x1,y1,x2,y2, grid_width,grid_height,c); grid[y_cell*grid_width + x_cell].push_back(Point2f((float)x, (float)y)); corners.push_back(Point2f((float)x, (float)y)); ++ncorners; if( maxCorners > 0 && (int)ncorners == maxCorners ) break; } } } else { for( i = 0; i < total; i++ ) { int ofs = (int)((const uchar*)tmpCorners[i] - eig.data); int y = (int)(ofs / eig.step); int x = (int)((ofs - y*eig.step)/sizeof(float)); corners.push_back(Point2f((float)x, (float)y)); ++ncorners; if( maxCorners > 0 && (int)ncorners == maxCorners ) break; } } /* for( i = 0; i < total; i++ ) { int ofs = (int)((const uchar*)tmpCorners[i] - eig.data); int y = (int)(ofs / eig.step); int x = (int)((ofs - y*eig.step)/sizeof(float)); if( minDistance > 0 ) { for( j = 0; j < ncorners; j++ ) { float dx = x - corners[j].x; float dy = y - corners[j].y; if( dx*dx + dy*dy < minDistance ) break; } if( j < ncorners ) continue; } corners.push_back(Point2f((float)x, (float)y)); ++ncorners; if( maxCorners > 0 && (int)ncorners == maxCorners ) break; } */ } } CV_IMPL void cvGoodFeaturesToTrack( const void* _image, void*, void*, CvPoint2D32f* _corners, int *_corner_count, double quality_level, double min_distance, const void* _maskImage, int block_size, int use_harris, double harris_k ) { cv::Mat image = cv::cvarrToMat(_image), mask; cv::vector corners; if( _maskImage ) mask = cv::cvarrToMat(_maskImage); CV_Assert( _corners && _corner_count ); cv::goodFeaturesToTrack( image, corners, *_corner_count, quality_level, min_distance, mask, block_size, use_harris != 0, harris_k ); size_t i, ncorners = corners.size(); for( i = 0; i < ncorners; i++ ) _corners[i] = corners[i]; *_corner_count = (int)ncorners; } /* End of file. */