方式1:
Mat mat_mean, mat_stddev; cv::meanStdDev(img, mat_mean, mat_stddev); double value = mat_mean.at<double>(0, 0);
方式2:
double value = mean(img)[0];
方式1:
Mat mat_mean, mat_stddev; cv::meanStdDev(img, mat_mean, mat_stddev); double value = mat_mean.at<double>(0, 0);
方式2:
double value = mean(img)[0];