Re: [Gimp-developer] Purple fringing removal extension

[Martin Jambon <gimp mjambon com>]

On 07/14/2012 03:56 PM, Robert Krawitz wrote:
> On Sun, 15 Jul 2012 01:19:52 +0400, Alexandre Prokoudine wrote:
>> On Sat, Jul 14, 2012 at 12:35 PM, Martin Jambon wrote:
>>> Hi,
>>>
>>> I am totally new here but I wrote a standalone program that does a
>>> decent job of removing purple fringing from photos, and I would like to
>>> be able to implement the same functionality for Gimp.
>>>
>>> Here are some examples of what it does:
>>>
>>>   http://mjambon.com/purple-fringe/examples.html
>>>
>>> My algorithm needs to perform pixelwise operations (+, -, min, max
>>> between two channels; scaling of one channel) but I also would prefer
>>> something that is easy to install (for users) and easy to maintain (for me).
>>>
>>> The OCaml source code is here; it should give an idea of what's needed:
>>>
>>>   https://github.com/mjambon/purple-fringe/blob/master/src/unpurple.ml
>>>
>>> (see functions make_purple_blur and remove_purple_blur, lines 103-177)
>>>
>>>
>>> My questions are:
>>>
>>> 1. Is it possible to do that using a Gimp script?
>>>
>>> 2. If so, Scheme or Python?
>>>
>>> 3. If a plugin makes more sense, will average users be able to install
>>> it for themselves or would I have to wait for the inclusion in some
>>> standard precompiled distribution?
>>
>> Just in case, are you aware of http://kcd.sourceforge.net/fix-ca.php ?
> 
> BTW, Martin, I'd suggest optimizing it -- 1 second/megapixel is a fair
> amount of time for someone processing a lot of 18 MP images, and people
> with Nikon D800's will be even more unhappy.  You may also want to talk
> with the ImageMagick folks about getting it included there.  This could
> become a very important part of a photographic workflow.

Right. I'd like to try built-in implementations of blur algorithms
first, since it is likely to remain the bottleneck of my algorithm. If
that's not enough, some parallelization should help.


Martin