harris corner detection 实现

来源：互联网发布：网络鉴宝是骗局吗编辑：程序博客网时间：2024/05/18 18:20
关于harris corner的原理，参照 http://en.wikipedia.org/wiki/Corner_detection
以下为自己的实现，并于opencv进行了比较
//////////////////////////////////////////////////////////////////////// implement harris corner detection algorithm by my self and then compare it with the API in opencv//////////////////////////////////////////////////////////////////** * @brief myCornerHarris * @param src_ input image, only has one channel * @param dst all pixels' reponse R = det(M) - k*trace(M)^2 ,M is auto correclation matrix; * @param blockSize * @param kSize * @param k * @param borderType */void myCornerHarris(const Mat& src_, Mat& dst, int blockSize, int kSize, double k){    Mat src;    src_.copyTo(src);    dst.create(src.size(),CV_32F);    int depth = src.depth();    double scale = (double)(1 << ((kSize > 0 ? kSize : 3) - 1)) * blockSize;    if( depth == CV_8U )        scale *= 255.;    scale = 1./scale;    assert(src.type() == CV_8UC1 || src.type() == CV_32FC1);    Mat dx,dy;    Sobel(src,dx,CV_32F,1,0,kSize,scale,0);    Sobel(src,dy,CV_32F,0,1,kSize,scale,0);    Size size = src.size();    Mat cov(size,CV_32FC3);    int i,j;    for(i = 0;i < size.height;i++){        float *covData = (float*)(cov.data + i*cov.step);        const float *dxData = (const float*)(dx.data + i*dx.step);        const float *dyData = (const float*)(dy.data + i*dy.step);        for(j = 0;j < size.width;j++){            float dx_ = dxData[j];            float dy_ = dyData[j];            covData[3*j] = dx_*dx_;            covData[3*j+1] = dx_*dy_;            covData[3*j+2] = dy_*dy_;        }    }    // compute the sum of blocksize window    boxFilter(cov,cov,cov.depth(),Size(blockSize,blockSize),Point(-1,-1),false);    if(cov.isContinuous() && dst.isContinuous()){        size.width *= size.height;        size.height = 1;    }    else        size = dst.size();    for(i = 0;i < size.height;i++){        float *dstData = (float*)(dst.data + i*dst.step);        const float *covData = (const float*)(cov.data + i*cov.step);        for(j = 0;j < size.width;j++){            float a = covData[3*j];            float b = covData[3*j+1];            float c = covData[3*j+2];            dstData[j] = a*c - b*b - k*(a+c)*(a+c);        }    }}void testCornerHarris(int argc, char* argv[]){    if(argc != 2){        PRINT "ERROR : program image\n";        return;    }    if(!csg::isFileExsit(argv[1])){        PRINT "",argv[1],"does not exsit\n";        return;    }    Mat src = imread(argv[1],CV_LOAD_IMAGE_COLOR);    if(!src.data){        PRINT "image data error\n";        return;    }    Mat grayImage;    cvtColor(src,grayImage,CV_BGR2GRAY);   //compare the difference of my cornerHarris and opencv cornerHarris    Mat myHarrisCorner, harrisCorner;    int blockSize = 3;    int kSize = 3;    double k = 0.04;    cornerHarris(grayImage,harrisCorner,blockSize,kSize,k);    myCornerHarris(grayImage,myHarrisCorner,blockSize,kSize,k);    double error = 0.0;    error = norm(myHarrisCorner,harrisCorner,NORM_L2);    PRINT "error : ",error;}
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