Solved by Shisho_Sama in post #9 
              
              
                Yes, the c++ side is like this, no matter what I do, it stays the same ( at least in the output) 
update: 
it turns out after the very same input was used (i.e. used cv both in python and c++ to read the image) 
the channels had to be the same as well. the stupid me had placed the cv::cvtColor(image…