Created attachment 5726 the resulting bmp Hello, i was playing arroung with a bmp file in nano and deleted some chars. The resulting bmp file shows now different colors every time i open it. its probably not only a bug of ristretto because on the upload window the preview also changes colors. But i'm kind of a noob with linux so my guess was its ristretto...
I confirm this bug with the latest version from git(re0eb867). Steps: Open the attached file with ristretto Zoom to fit window(Ctrl+=) Open preferences Toggle 'Limit rendering quality' multiple times Well, this might occur because this file is malformed and because ristretto allows a very large zoom, so while blurring those strange things happens. Awkward as the results are random. Just for comparison: GIMP just rendered the first row of pixels as black. Viewnior doesn't allow large zooms, but one can see that the first two/three pixels are black. Pinta rendered the first two pixels as black. IMHO this should be closed as WONTFIX due the malformed bitmap, but it's up to the maintainer to fix this or not.
There's probably no correct way to show a malformed image - closing.