GFTT特征点检测

角点检测，避免出现聚簇现象

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,接口如下　　

Ptr<GFTTDetector> create( int maxCorners=1000, double qualityLevel=0.01, double minDistance=1,int blockSize=3, bool useHarrisDetector=false, double k=0.04 );

maxCorners 最大角点数目 

qualityLevel角点可以接受的最小特征值,一般0.1或者0.01,不超过1 

minDistance 加点之间的最小距离

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 一般为0.04

int main(int argc,char* argv[])
{
    Mat srcImage = imread("F:\\opencv\\OpenCVImage\\FeatureDetectSrc1.jpg");
    Mat srcGrayImage;
    if (srcImage.channels() == 3)
    {
        cvtColor(srcImage,srcGrayImage,CV_RGB2GRAY);
    }
    else
    {
        srcImage.copyTo(srcGrayImage);
    }
    vector<KeyPoint>detectKeyPoint;
    Mat keyPointImage1,keyPointImage2;

    Ptr<GFTTDetector> gftt = GFTTDetector::create();
    gftt->detect(srcGrayImage,detectKeyPoint);
    drawKeypoints(srcImage,detectKeyPoint,keyPointImage1,Scalar(0,0,255),DrawMatchesFlags::DRAW_RICH_KEYPOINTS);
    drawKeypoints(srcImage,detectKeyPoint,keyPointImage2,Scalar(0,0,255),DrawMatchesFlags::DEFAULT);

    imshow("src image",srcImage);
    imshow("keyPoint image1",keyPointImage1);
    imshow("keyPoint image2",keyPointImage2);

    imwrite("F:\\opencv\\OpenCVImage\\FeatureDetectSrc1GFTTKeyPointImageDefault.jpg",keyPointImage2);

    waitKey(0);
    return 0;
}