Dithering quality will be affected by the assumed monitor gamma (I believe). I just attempted to calibrate mine, and still found banding in this image though.
Most monitors ought to have a gamma of roughly 2.2 (or calibrated to that), unless you happen to have a (older?) Mac - then its 1.8. (Althuogh that is still more an OS issue than hardware). I originally put the banding in this image down to the inevitably reduced colour gamut available on your average 18bit laptop LCD panel. (My HP laptop has a pretty awful colour rendition even then - gamma varies quite a lot between R, G and B channels and appears to need a more complex correction curve than Linux drivers currently allow). I just tried viewing the image on my HP 2475w monitor (a 24bit "commercial grade" monitor with an IPS panel, and decent colour rendition), and the splash screen still looks pretty badly banded. It looks nicer than my laptop screen due to its wider gamut, and more faithful colour rendition - but still pretty poor. With these dark themes, and subtle colour variations - it is really surprising how different the colours and tones are between monitors, so I'd imagine it will always be hard to get the Ubuntu branding looking consistent with these tones present. Does the original artist have the desigin files available in a vector format? It might be possible to re-export the gradients etc.. If the artwork was produced as a bitmap, the banding might have been introduced due to working in 8bit per pixel colours only, and applying many different filters / effects etc.., eventually causing quantization problems in the image. -- Poor splash image quality (high banding) https://bugs.launchpad.net/bugs/451880 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
