Opencv实现图像灰度线性变换

#include<opencv2/opencv.hpp>;
#include<iostream>
 
using namespace cv;
using namespace std;
 
int main(int argc, char** argv)
{
 Mat src,dst;
 src = imread("1.jpg");
 if (!src.data)
 {
 cout << "could not load image" << endl;
 return -1;
 }
 namedWindow("input", CV_WINDOW_AUTOSIZE);
 imshow("input", src);
 
 int rows = src.rows;
 int cols = src.cols;
 float alpha = 1.2, beta = 10;
 dst = Mat::zeros(src.size(), src.type());
 for (int row = 0; row < rows; row++) {
 for (int col = 0; col < cols; col++) { 
  if (src.channels() == 3) {
  int b = src.at<Vec3b>(row, col)[0];
  int g = src.at<Vec3b>(row, col)[1];
  int r = src.at<Vec3b>(row, col)[2];
  dst.at<Vec3b>(row, col)[0] = saturate_cast<uchar>((alpha*b + beta));
  dst.at<Vec3b>(row, col)[1] = saturate_cast<uchar>((alpha*g + beta));
  dst.at<Vec3b>(row, col)[2] = saturate_cast<uchar>((alpha*r + beta));
  }
  else if(src.channels()==1){
  int v = src.at<uchar>(row, col);
  dst.at<uchar>(row, col) = saturate_cast<uchar>(alpha*v + beta);
  }
 }
 }
 namedWindow("output", CV_WINDOW_AUTOSIZE);
 imshow("output", dst);
 waitKey(0);
 return 0;
}