1 #include <opencv2\opencv.hpp>
  2 #include <iostream>
  3 #include <string>
  4
  5 using namespace std;
  6
  7 #define HARRIS
  8
  9 cv::RNG rng(12345);
 10
 11 void calEigen2x2(cv::Mat cov,cv::Mat &eigenValue)
 12 {
 13     int height = cov.rows;
 14     int width = cov.cols;
 15
 16     float *pCov = (float*)cov.data;
 17     float *pEigenValue = (float*)eigenValue.data;
 18     for (int i = 0; i < height; i++)
 19     {
 20         for (int j = 0; j < width; j++)
 21         {
 22             double a = pCov[(i*width + j) * 3 + 0];
 23             double b = pCov[(i*width + j) * 3 + 1];
 24             double c = pCov[(i*width + j) * 3 + 2];
 25
 26             double tmp1 = (a + c) / 2.;
 27             double tmp2 = sqrtf(b*b + (a - c)*(a - c) / 4.);
 28
 29             double alpha = tmp1 - tmp2;
 30             double beta = tmp1 + tmp2;
 31
 32             pEigenValue[(i*width + j) * 2 + 0] =(float) alpha;
 33             pEigenValue[(i*width + j) * 2 + 1] =(float) beta;
 34         }
 35     }
 36 }
 37
 38 void myCalEigenValues(cv::Mat srcImg, cv::Mat &eigenValue, int covWin, int sobelWin)
 39 {
 40     //求微分
 41     cv::Mat sobelx, sobely;
 42     cv::Sobel(srcImg, sobelx, CV_32FC1, 1, 0, sobelWin, 1. / (255*12), 0, 4);
 43     cv::Sobel(srcImg, sobely, CV_32FC1, 0, 1, sobelWin, 1. / (255*12), 0, 4);
 44
 45     cv::Mat cov = cv::Mat::zeros(srcImg.size(), CV_32FC3);
 46     int height = srcImg.rows;
 47     int width = srcImg.cols;
 48     float *pSobelX = (float*)sobelx.data;
 49     float *pSobelY = (float*)sobely.data;
 50     float *pCov = (float*)cov.data;
 51     for (int i = 0; i < height; i++)
 52     {
 53         for (int j = 0; j < width; j++)
 54         {
 55             float dx = pSobelX[i*width + j];
 56             float dy = pSobelY[i*width + j];
 57
 58             pCov[(i*width + j) * 3 + 0] = dx*dx;
 59             pCov[(i*width + j) * 3 + 1] = dx*dy;
 60             pCov[(i*width + j) * 3 + 2] = dy*dy;
 61         }
 62     }
 63
 64     cv::boxFilter(cov, cov, cov.depth(), cv::Size(covWin, covWin), cv::Point(-1, -1), false, 4);
 65
 66     calEigen2x2(cov, eigenValue);
 67 }
 68
 69 void main()
 70 {
 71     string imgPath = "data/srcImg/0.png";
 72     cv::Mat srcImg = cv::imread(imgPath, 1);
 73     cv::Mat grayImg;
 74     cv::cvtColor(srcImg, grayImg, CV_BGR2GRAY);
 75     int height = srcImg.rows;
 76     int width = srcImg.cols;
 77
 78     cv::Mat eigenValue = cv::Mat::zeros(grayImg.size(), CV_32FC2);
 79     int covWin = 3, sobelWin = 3;
 80     myCalEigenValues(grayImg, eigenValue, covWin, sobelWin);
 81
 82     cv::Mat Mc = cv::Mat::zeros(grayImg.size(), CV_32FC1);
 83 #ifndef HARRIS
 84     //计算特征表达式值
 85     for (int i = 0; i<height; i++)
 86     {
 87         for (int j = 0; j < width; j++)
 88         {
 89             float alpha = eigenValue.at<float>(i, j*2+0);
 90             float beta = eigenValue.at<float>(i, j*2+1);
 91
 92             Mc.at<float>(i, j) = alpha*beta - 0.04f*pow((alpha + beta), 2);
 93         }
 94     }
 95 #else //ShiTomasi
 96     for (int i = 0; i<height; i++)
 97     {
 98         for (int j = 0; j < width; j++)
 99         {
100             float alpha = eigenValue.at<float>(i, j * 2 + 0);
101             float beta = eigenValue.at<float>(i, j * 2 + 1);
102
103             float minEigenValue = (alpha > beta) ? (beta) : (alpha);
104
105             Mc.at<float>(i, j) = minEigenValue;
106         }
107     }
108 #endif
109
110     double minVal, maxVal;
111     cv::minMaxLoc(Mc, &minVal, &maxVal, 0, 0, cv::Mat());
112
113     double thresh = (maxVal + minVal) / 2.;
114     for (int i = 0; i < height; i++)
115     {
116         for (int j = 0; j < width; j++)
117         {
118             double value = (double)Mc.at<float>(i, j);
119             if (value > thresh)
120             {
121                 cv::circle(srcImg, cv::Point(j, i), 4, cv::Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255)), -1, 8, 0);
122             }
123         }
124     }
125
126     cv::namedWindow("show", 0);
127     cv::imshow("show", srcImg);
128     cv::waitKey(0);
129 }