[Gegl-developer] Scanline processing in a GeglOperation

[Hans Petter Jansson]

[Sorry if this gets posted twice; I managed to send the first one with
the wrong From: address].

Hi. I've looked through the docs and (briefly) the list archives, but I
can't figure out if it's possible to efficiently process the input to a
GeglOperation in a scanline fashion -- i.e. with access to, and
outputting, only the pixels of a single, complete row at a time.

I'm trying to write a Floyd-Steinberg dithering implementation, and the
way the algorithm is specified, the order in which pixels are processed
is significant. It "pushes" the quantization error ahead of it to the
next pixel and to pixels on the next scanline. For more background see
[1].

Is there an efficient way of doing this in a GEGL op?

[1] http://en.wikipedia.org/wiki/Floyd-Steinberg_dithering

-- 
Hans Petter