Re: [Gimp-developer] Precision Conversion Dithering and Triangular wave gradient issues

[Michael Natterer <mitch gimp org>]

On Tue, 2014-09-02 at 11:54 -0400, Elle Stone wrote:
> Precision Conversion Dithering and Triangular wave gradient both fail:
>
> 1. The Precision Conversion Dithering doesn't seem to work at 32- and 
> 64-bit precision, at least not on my computer (lower precisions work). 
> If I say "yes, dither", one CPU runs at 100% forever, even with a very 
> small image, accomplishing nothing at all. The only way to make it stop 
> is to kill the GIMP process from the command line. The terminal output 
> looks like this:
>
> (gimp-2.9:2479): GLib-GObject-WARNING **: value "32" of type 'gint' is 
> invalid or out of range for property 'red-bits' of type 'gint'

Indeed, it seems the color-reduction GEGL op we use for dithering only
handles up to 16 bit of precision. I think you should file a bug against
the GEGL op so we can track the issue.

For the time being, I'll change the GIMP code not to run into
that case by not allowing to choose dithering for > 16 bit.

Regards,
--Mitch