On 07/13/2010 10:28 AM, Przemys?aw Zych wrote:

Hi,

As a part of my student project for "Optimizing Open-Source Applications" at Warsaw University I have speed up despeckle plug-in for gimp.

Original version of the plugin run 56seconds for 1024x768 image with despeckle radius 30 and adaptive flag turned off (on my Intel Macbook 2.1GHz). My optimized version with the same settings completes the task in 3.5 seconds with the same image quality :-)

Sources for this optimized plug-in can be downloaded from here: http://students.mimuw.edu.pl/~pz248275/despeckle.c

What should I do to get this to the gimp repository? Should I change the copyright header?

Hi!

That sounds great.

To maximize chances of getting this into GIMP:

1. Create a regression test for the despecle plug-in that is run with 'make check'. This is a great way to convince us that your optimization in fact does not change the output, only improves performance.
2. Create a patch, following the instructions here: http://www.gimp.org/bugs/howtos/submit-patch.html

Since your change is significant, feel free to add yourself to the copyright header.

Regards,
Martin

On Tue, 2010-07-13 at 10:49 +0200, Martin Nordholts wrote:

On 07/13/2010 10:28 AM, Przemys?aw Zych wrote:

Hi,

As a part of my student project for "Optimizing Open-Source Applications" at Warsaw University I have speed up despeckle plug-in for gimp.

Original version of the plugin run 56seconds for 1024x768 image with despeckle radius 30 and adaptive flag turned off (on my Intel Macbook 2.1GHz). My optimized version with the same settings completes the task in 3.5 seconds with the same image quality :-)

Sources for this optimized plug-in can be downloaded from here: http://students.mimuw.edu.pl/~pz248275/despeckle.c

What should I do to get this to the gimp repository? Should I change the copyright header?

Hi!

That sounds great.

To maximize chances of getting this into GIMP:

1. Create a regression test for the despecle plug-in that is run with 'make check'. This is a great way to convince us that your optimization in fact does not change the output, only improves performance.

Well, as far as I can see the current implementation of the despeckle plug-in does not match the expectations. IMO it is buggy. Thus we should not absolutely require that the result does not change. But it would be desirable to get fixes to the algorithm submitted separately from optimizations.

It would also help a lot if the patch followed the GIMP coding style. Please see the file HACKING in the GIMP source tree.

Sven

On 07/13/10 19:52, Sven Neumann wrote:

On Tue, 2010-07-13 at 10:49 +0200, Martin Nordholts wrote:

On 07/13/2010 10:28 AM, Przemys?aw Zych wrote:

Hi,

As a part of my student project for "Optimizing Open-Source Applications" at Warsaw University I have speed up despeckle plug-in for gimp.

Original version of the plugin run 56seconds for 1024x768 image with despeckle radius 30 and adaptive flag turned off (on my Intel Macbook 2.1GHz). My optimized version with the same settings completes the task in 3.5 seconds with the same image quality :-)

Sources for this optimized plug-in can be downloaded from here: http://students.mimuw.edu.pl/~pz248275/despeckle.c

What should I do to get this to the gimp repository? Should I change the copyright header?

Hi!

That sounds great.

To maximize chances of getting this into GIMP:

1. Create a regression test for the despecle plug-in that is run with 'make check'. This is a great way to convince us that your optimization in fact does not change the output, only improves performance.

Well, as far as I can see the current implementation of the despeckle plug-in does not match the expectations. IMO it is buggy. Thus we should not absolutely require that the result does not change. But it would be desirable to get fixes to the algorithm submitted separately from optimizations.

It would also help a lot if the patch followed the GIMP coding style. Please see the file HACKING in the GIMP source tree.

Sven

hi,

I agree. I had to clean up some photos recently and ended up doing most of it by hand.

If you code produces the same kind of results with that much of a speed increase a patch would be worth providing. Kudos for achieving that level of speed up.

I guess by now you must have got a good feel for the way that part of the code base works so if you can write a despeckle routing that does despeckle that would be a worthwhile contribution as well.

Thanks for you efforts.

/gg

On Tue, 2010-07-13 at 22:19 +0200, gg@catking.net wrote:

I agree. I had to clean up some photos recently and ended up doing most of it by hand.

If you code produces the same kind of results with that much of a speed increase a patch would be worth providing. Kudos for achieving that level of speed up.

The quality of results also very much depends on how the parameters are chosen. A speedup of the algorithm will make it easier to experiment with the parameters as it should also speed up the preview significantly.

So yes, we should try to get that patch into GIMP as soon as possible.

Sven