OpenCV学习第七篇：调整图像亮度和对比度

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

using namespace cv;
using namespace std;

int main(int argc, char** argv) {
Mat src, dst;
src = imread("F:/识图/测试1.JPG");
if (src.empty())
{
printf("没有找到图片！");
return -1;
}

char input_win[] = "input image";
namedWindow(input_win, CV_WINDOW_AUTOSIZE);
imshow(input_win, src);

int height = src.rows;
int width = src.cols;
dst = Mat::zeros(src.size(), src.type());
float alpha = 2;
float beta = 30;

Mat m1;
src.convertTo(m1, CV_32F);

for (int row = 0; row < height; row++)
{
for (int col = 0; col < width; col++)
{
if (src.channels()==3)
{
float b = m1.at<Vec3f>(row, col)[0];
float g = m1.at<Vec3f>(row, col)[1];
float r = m1.at<Vec3f>(row, col)[2];

dst.at<Vec3b>(row, col)[0] = saturate_cast<uchar>(b*alpha + beta);
dst.at<Vec3b>(row, col)[1] = saturate_cast<uchar>(g*alpha + beta);
dst.at<Vec3b>(row, col)[2] = saturate_cast<uchar>(r*alpha + beta);
}
else if(src.channels()==1)
{
float v = src.at<uchar>(row, col);
dst.at<uchar>(row, col) = saturate_cast<uchar>(v*alpha + beta);
}
}
}
char output_title[] = "contrast and brightness change demo!";
namedWindow(output_title, CV_WINDOW_AUTOSIZE);
imshow(output_title, dst);
waitKey(0);
return 0;
}