[Gegl-developer] Scanline processing in a GeglOperation

[Øyvind Kolås]

On Mon, Apr 21, 2008 at 11:18 AM, Øyvind Kolås <pippin at gimp.org> wrote:
>  Thus to correctly implement floyd steinberg you would actually have to
>  request the processing of the entire image and not piece by piece thus
>  losing the ability to handle larger than RAM images.

This isn't entirely true as you can fetch and store individual
scanlines when reading/writing from the involved GeglBuffers as the op
is processing for the entire image, nevertheless such an op would need
the entire image as source data to update the bottomrightmost pixel.
And it would make future scheduling and paralellization of graphs
involving such ops much harder than needed. I imagine either green
noise or blue noise based halftoning/dither might have properties that
align better with the GEGL architecture, not to mention that those
approaches do not suffer from similar artifacts of repeating patterns
that floyd steinberg dithering suffers from.

/Øyvind K.
-- 
«The future is already here. It's just not very evenly distributed»
 -- William Gibson
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