https://bugs.kde.org/show_bug.cgi?id=411922
--- Comment #7 from Ahab Greybeard <ahab.greybe...@hotmail.co.uk> --- Created attachment 122681 --> https://bugs.kde.org/attachment.cgi?id=122681&action=edit Apparently blank .png file with colour values set Your image has content that is detected by the Prewitt filter (and Height to Normal Map)and shown as the 'staircase'. If you take the image layer and split the alpha to a mask, then turn off the mask, this is clearly visible. It seems that these filters are sensitive to colour value of the pixels and appear to disregard the alpha values. If you paint and erase, the alpha is set to zero but the colour values remain which would (and does) cause unexpected artifacts. I attach the file 'hiddenU.png' which demonstrates this. I don't know if the Prewitt filter (and others) are supposed to do this. The Prewitt filter in GIMP does not do this. -- You are receiving this mail because: You are watching all bug changes.
