Hi Martin, I still have problems solving this overall problem. First I do not normalize the data anymore because I did not do that in my training routine in Python. When I print out the Mat object, I get the values I expected - between 0 and 255. After thi I printed ia Mat::data and there were only cryptical signs. Then I load the data into the tensor object as the code shows it. In the loop I print the batch.data and it shows the number 221 for each pixel value wich is very confusing for me. Do you have a clue, why it behaves like it does?