Red Hat Bugzilla – Bug 66261
gdk-pixbuf should dither images in 16bpp
Last modified: 2007-03-26 23:53:50 EDT
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Description of problem:
gdk-pixbuf currently does not dither images in 16bpp; visible banding occurs.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. View images used in GTK+ widgets.
2. Horrible banding occurs on gradients and alpha gradients.
Expected Results: Images displayed using GTK+2, such as those in Anaconda,
up2date, etc. should look fine in 16bpp, with no banding. Dithering would make
things look "normal".
It's not at all clear to me that changing 16bpp to dither at
GTK_DITHER_NORMAL level would be a compatible change... note
also in many cases the problem is that rendering is going
through the alpha-composited path, which can never be dithered.
Marking various no-need-to-be-private bugs public.
I think Owen is right. The docs for GdkRgbDither clearly define
that GDK_RGB_DITHER_NORMAL doesn't dither at 16bpp. This must be fixed
in the caller by using GDK_RGB_DITHER_MAX. I don't know how anaconda
displays its images...