Re: [Gimp-developer] Purple fringing removal extension

[Robert Krawitz <rlk alum mit edu>]

On Sun, 15 Jul 2012 00:54:50 -0700, Martin Jambon wrote:
> 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.

Have you profiled the code yet?
-- 
Robert Krawitz                                     <rlk alum mit edu>

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