by ʇolɐǝz ǝɥʇ qoq

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I would like to obtain an effect where pixels get spreaded locally. I tried to reproduce how such a filter would look, I hope you get the idea:





Note: here I ran a blur, aded noise and then added a lot of contrast to give a "spreading effect" and remove the noise in plain areas. But it wouldn't work with not-extreme colours (in the sense of contrast).

Edit: now that I've found the answer, here the official definition for the filter which describes best the effect:

The Spread filter swaps each pixel in the active layer or selection with another randomly chosen pixel by a user specified amount. It works on color transitions, not on plain color areas. No new color is introduced.

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This appears to be a dither rather than a blur. – AJ Henderson Jul 30 '13 at 16:12
It is unclear what you want. How is simple low pass filtering not what you are asking for? – Olin Lathrop Jul 30 '13 at 16:26
What software are you interested in? – Unapiedra Jul 30 '13 at 17:52
@Unapiedra : mostly free ones (Gimp,, but if it's only available on photoshop, I'll find a way. – BiAiB Jul 30 '13 at 19:17
Also, could you perhaps show what you are looking for with a sample photograph rather than colored scribbles? – mattdm Jul 30 '13 at 23:24

Well, finally I've found it in Gimp (french version).

Filtre > Bruit > Eparpiller (Filters > Noise > Scatter EDIT: Spread )

enter image description here

"Mélanger" et "Piquer" are good too(not sure the translations, maybe "melt" and "pick"). Can't believe I missed them.

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