Re: [Gegl-developer] Gegl Operation : Retinex

[scl <scl gplus gmail com>]

Hi,


On 18.12.2013 at 10:29 PM Joao S. O. Bueno wrote:
> It looks like this still remains to be rewritten for GEGL?

Looking at the [GEGL porting matrix] you are right.

> (what lead me to do this? I've hit the "retinex" filter description
> while translating the
> GIMP manual, and went happily to gimp master to check how retinex would
> behave in a 32 bit per channel image - just to find it was not there)

I just tried with a quite current master build on Linux and found it at
the end of the Colors menu. You can find the code in GIMP 2.8 and
master sources - it's /plug-ins/common/contrast-retinex.c.

I looked in the help and found the [webpage of the plug-ins author]. It
seems the algorithm dates back to 1996, which is quite old and in the
meantime there happened [further research] about the topic.

IMHO to go with GIMPs product vision to provide cutting-edge and
fast algorithms it should considered to first check whether now exist
improvements to the 1996 Retinex algorithm (resp. Rahman Tone-mapping
operator). Perhaps there's also something usable in the former years'
GSOC GEGL branches. The best would surely be if the potential
contributor came to IRC and spoke with the devs.

Kind regards,

Sven



[GEGL porting matrix]:
http://wiki.gimp.org/index.php/Hacking:Porting_filters_to_GEGL

[webpage of the plug-ins author]:
http://www-prima.inrialpes.fr/pelisson/MSRCR.php

[further research]:
http://scholar.google.com/scholar?q=multiscale+retinex&hl=de&as_sdt=1%2C5&as_ylo=1996&as_yhi=2013