[Gegl-developer] tile size in filters

[Øyvind Kolås]

On Mon, Oct 20, 2008 at 3:56 PM, Dierk Fröhling <dfroehling at aycan.de> wrote:
> Hans Petter Jansson wrote:
>> On Thu, 2008-10-09 at 11:08 +0200, Dierk Fröhling wrote:
>>
>>> I need to handle all pixels of an image in one tile for my new filter.
>>> The problem is that every pixel in the filtered image should depend on
>>> values from all other pixels...
..
>> I wrote a color reduction filter that does Floyd-Steinberg dithering,
>> where each pixel depends on all previous pixels (the bottom-right pixel
>> depends on the entire image). It should be among the workshop filters.
>> Maybe that'd be useful to look at.
>
> This worked up to a certain size of images - but with an image with 3112
> x 4200 pixels I get this message from gegl:
>
> ** Message: unable to write tile data to self: No space left on device
> (-1/131072 bytes written)
>
> There is enough space in my /tmp directory and all other possible
> working directories for gegl - 2GB of memory should be enough as well...
> It's not that my filter won't work at all with these big images - but
> only in parts. It seems that gegl splits it into tiles again...

The place that GEGL probably tries to swap is ~/.gegl/swap I'm not
sure what is going on here. Does this happen with the color reduction
filter as well? Please open a bug
so we can track this issue, perhaps even with an example XML file
provoking the issue (perhaps using fractal-explorer as source data or
some similar synthethic buffer as input.)

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