以前角点检测的时候提到过角点检测的算法,第一个是cornerHarris计算角点,可是这种角点检测算法容易出现聚簇现象以及角点信息有丢失和位置偏移现象,因此后面又提出一种名为算法
shi_tomasi的角点检测算法,名称goodFeatureToTrack,opencv的feature2D接口集成了这种算法,名称为GFTTDetector,接口以下spa
Ptr<GFTTDetector> create( int maxCorners=1000, double qualityLevel=0.01, double minDistance=1,code
int blockSize=3, bool useHarrisDetector=false, double k=0.04 );blog
maxCorners 最大角点数目 qualityLevel角点能够接受的最小特征值,通常0.1或者0.01,不超过1 minDistance 加点之间的最小距离接口
blockSize倒数自相关矩阵的邻域范围 useHarrisDetector 是否使用角点检测 khessian自相关矩阵的相对权重系数 通常为0.04it
使用代码以下opencv
1 int main(int argc,char* argv[]) 2 { 3 Mat srcImage = imread("F:\\opencv\\OpenCVImage\\FeatureDetectSrc1.jpg"); 4 Mat srcGrayImage; 5 if (srcImage.channels() == 3) 6 { 7 cvtColor(srcImage,srcGrayImage,CV_RGB2GRAY); 8 } 9 else 10 { 11 srcImage.copyTo(srcGrayImage); 12 } 13 vector<KeyPoint>detectKeyPoint; 14 Mat keyPointImage1,keyPointImage2; 15 16 Ptr<GFTTDetector> gftt = GFTTDetector::create(); 17 gftt->detect(srcGrayImage,detectKeyPoint); 18 drawKeypoints(srcImage,detectKeyPoint,keyPointImage1,Scalar(0,0,255),DrawMatchesFlags::DRAW_RICH_KEYPOINTS); 19 drawKeypoints(srcImage,detectKeyPoint,keyPointImage2,Scalar(0,0,255),DrawMatchesFlags::DEFAULT); 20 21 imshow("src image",srcImage); 22 imshow("keyPoint image1",keyPointImage1); 23 imshow("keyPoint image2",keyPointImage2); 24 25 imwrite("F:\\opencv\\OpenCVImage\\FeatureDetectSrc1GFTTKeyPointImageDefault.jpg",keyPointImage2); 26 27 waitKey(0); 28 return 0; 29 }
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