OpenCV （二）掩膜操作

#include <opencv2/opencv.hpp>
#include <iostream>
#include <math.h>

using namespace cv;

int main(int argc, char** argv) {
 Mat src, dst;
 src = imread("D:/OpenCVtest/image/hao.jpg");
 if (!src.data) {
  　　printf("could not load image... ");
  　　return -1;
 }
 namedWindow("input image", CV_WINDOW_AUTOSIZE);
 imshow("input image", src);

 /*
 int cols = (src.cols-1) * src.channels();
 int offsetx = src.channels();
 int rows = src.rows;

 dst = Mat::zeros(src.size(), src.type());
 for (int row = 1; row < (rows - 1); row++) {
　　  const uchar* previous = src.ptr<uchar>(row - 1);
  　　const uchar* current = src.ptr<uchar>(row);
 　　 const uchar* next = src.ptr<uchar>(row + 1);
  　　uchar* output = dst.ptr<uchar>(row);
 　　 for (int col = offsetx; col < cols; col++) {
  　　 output[col] = saturate_cast<uchar>(5 * current[col] - (current[col- offsetx] + current[col+ offsetx] + previous[col] + next[col]));
 　　 }
　 }
 */
 double t = getTickCount();
 Mat kernel = (Mat_<char>(3, 3) << 0, -1, 0, -1, 5, -1, 0, -1, 0);
 filter2D(src, dst, src.depth(), kernel);
 double timeconsume = (getTickCount() - t) / getTickFrequency();
 printf("tim consume %.2f ", timeconsume);

 namedWindow("contrast image demo", CV_WINDOW_AUTOSIZE);
 imshow("contrast image demo", dst);

 waitKey(0);
 return 0;
}

 

原理：