How to get image pixel brightness and contrast in OpenCv c++? - c++

Question

How to get the brightness and constrast of range of pixel and apply it to set a gradient on another image in opencv c++?
I've tried to do that with this code
but I didn't get a good result
I want to apply the brightness and constrast of second part of image1 to the first part of image2 to apply an gradiant. the final goal is to stitch the two images
Mat image = imread("1.jpg" );
Mat image2 = imread("2.jpg" );
const int darkness_threshold = 128;
cv::Mat hsv;
cvtColor(image, hsv, COLOR_BGR2HSV);
const auto result = cv::mean(hsv);
cv::Mat hsv2;
cvtColor(image2, hsv2, COLOR_BGR2HSV);
const auto result2 = cv::mean(hsv2);
cout<<"resultat1: "<<result<<endl;
cout<<"resultat2: "<<result2<<endl;
Mat new_image = Mat::zeros( image.size(), image.type() );
double alpha = result2[0] - result[0];
double beta = result2[2] - result[2];
for( int y = 0; y < image.rows; y++ ) {
for( int x = 0; x < image.cols; x++ ) {
for( int c = 0; c < image.channels(); c++ ) {
new_image.at<Vec3b>(y,x)[c] =
saturate_cast<uchar>( alpha*image.at<Vec3b>(y,x)[c] + beta );
}
}
}
namedWindow("New Image",WINDOW_NORMAL);
imshow("New Image", new_image);
namedWindow("Image2",WINDOW_NORMAL);
imshow("Image2", image2);
imwrite("imgs1.jpg",new_image);
imwrite("imgs2.jpg",image2);
waitKey();
return 0;