Hi, it’s possible that even with the tiff utility that the channel information is still too narrow for NLP to make any changes. Take a look at your histograms for each color channel and see if any or missing or very narrow. You can try running the gamma utility again and choose a higher output gamma (like 4 or 5) and see if that helps. If you still encounter issues, please post more information and links to the image in the bug reporting thread: