通過影象灰度線性變換提高影象對比度和亮度,原影象為src，目標影象為dst，則dst(x,y) = * src(x,y) + 。

不僅對單通道影象可以做灰度線性變換，對三通道影象同樣可以。

#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;
}
 

 執行結果如下：