opencv图像对比度和亮度调整

#include <istream>
#include <opencv2/opencv.hpp>

using namespace cv;
using namespace std;

int main(int argc, char **argv) {
    Mat src, dst;
    //    加载图片
    src = imread("../../picture/bg1.webp", 1);
    if (!src.data) {
        printf("No image data \n");
        return -1;
    }
    namedWindow("src", WINDOW_AUTOSIZE);
    imshow("src", src);
    int rows = src.rows;
    int cols = src.cols;
    dst = Mat::zeros(src.size(), src.type());
    float alpha = 1.2;
    float beta = 10;
    for (int row = 0; row < rows; row++) {
        for (int col = 0; col < cols; col++) {
            if (src.channels() == 3) {
                float a = src.at<Vec3b>(row, col)[0];
                float b = src.at<Vec3b>(row, col)[1];
                float c = src.at<Vec3b>(row, col)[2];
                dst.at<Vec3b>(row, col)[0] = saturate_cast<uchar>(alpha * a + beta);
                dst.at<Vec3b>(row, col)[1] = saturate_cast<uchar>(alpha * b + beta);
                dst.at<Vec3b>(row, col)[2] = saturate_cast<uchar>(alpha * c + beta);
            } else if (src.channels() == 1) {
                float d = src.at<uchar>(row, col);
                dst.at<uchar>(row, col) = saturate_cast<uchar>(alpha * d + beta);
            }
        }
    }
    namedWindow("dst", WINDOW_AUTOSIZE);
    imshow("dst", dst);
    //    等待按键
    waitKey(0);
    return 0;
}