imread, imwrite , image color

edit

Hello everyone.

I'm trying to understand why the following thing happen...

I do

cv::Mat img = cv::imread(sourceImgPath, CV_LOAD_IMAGE_UNCHANGED);

and after that

cv::imwrite(sPath, img);

where the sPath contains the same file extension. The problem here is that the color from image change, is darker. Any explanation? Any solution to avoid this change?

Thank you.