Motion blur algorithms

[Calculemus]

I need to implement motion blur(linear, radial and zoom )algorithms
for an app I work on, like yours in GIMP.

In the .c file for motion blur it is not stated which source is used
for the math/algorithm.

Someone knows the source, paper, book or whatever that was
used as reference for implementing the motion blur algorithms?

Thanks

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[Guillermo Espertino (Gez)]

On 13/07/12 16:09, Calculemus wrote:
> I need to implement motion blur(linear, radial and zoom )algorithms
> for an app I work on, like yours in GIMP.

Hi
Is your application free software?
Please keep in mind that if you plan to publish your application and you
re-use code from GIMP you have to honor the GPL V3 license, publishing
the source code along the distributed binaries.

Releasing source code isn't a requirement if you don't plan to
distribute the application to the public and keep it for yourself.

Kind regards,
Gez.
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[Alexandre Prokoudine]

On Fri, Jul 13, 2012 at 11:09 PM, Calculemus wrote:
> I need to implement motion blur(linear, radial and zoom )algorithms
> for an app I work on, like yours in GIMP.
>
> In the .c file for motion blur it is not stated which source is used
> for the math/algorithm.
>
> Someone knows the source, paper, book or whatever that was
> used as reference for implementing the motion blur algorithms?

Why do you necessarily want the algo from GIMP?

There are probably dozens of approaches. Finding a paper is not a problem :)

http://graphics.snu.ac.kr/publications/conference_proceedings/2007-dykim-egwnp.pdf
+ its references could be a start.

Alexandre Prokoudine
http://libregraphicsworld.org
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[gg-6]

On 07/13/12 21:09, Calculemus wrote:

> I need to implement motion blur(linear, radial and zoom )algorithms
> for an app I work on, like yours in GIMP.
>
> In the .c file for motion blur it is not stated which source is used
> for the math/algorithm.
>
> Someone knows the source, paper, book or whatever that was
> used as reference for implementing the motion blur algorithms?
>
> Thanks
>
>

Motion blur is convolution of the image with a straight line ; defocus
blur with a filled circle. Deblurring is done by the inverse operation,
deconvolution.

This can be done as multiplication in the freq domain using  FFT or
convolution with a simple kernel image.

/gg
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[Calculemus]

Nope I am far from releasing :)

Why GIMP? It is the only open source for this kinda thing I know.

Easy to find papers, hmm? Ok, I am a student and need your advice
on this. Let's say I want to find a paper on an algorithm which I know
what it does, and that is all. Where do I search? I am member at
acm.org but usually they have very advanced papers.



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[Calculemus]

Alexandre, but that paper is for motion blur for animation
sequences. I just need motion blur for 2D images. It has
two parameters, angle and displacement.

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[Partha Bagchi-2]

On Fri, Jul 13, 2012 at 5:36 PM, Calculemus <[hidden email]> wrote:
> Alexandre, but that paper is for motion blur for animation
> sequences. I just need motion blur for 2D images. It has
> two parameters, angle and displacement.
>
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>

Hi,

I would think Wikipedia would be perfect for a student to start their
research? :)

I just typed "motion blur algorithm" within en.wikipedia.org and got
hundreds of hits.

Hope that helps.

Partha
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[gfxuser]

Hi Calcemus,

> Easy to find papers, hmm? Ok, I am a student and need your advice
> on this. Let's say I want to find a paper on an algorithm which I know
> what it does, and that is all. Where do I search? I am member at
> acm.org <http://acm.org> but usually they have very advanced papers.
>
>
nearly every scientific paper starts with a survey on existing papers
and research.
You could also look at Google scholar for survey or introduction papers.
Another way is to use www.metager.de (a meta search engine) and select
some scientific search engines there.
This should give you some hints or serve as starting point into a
particular topic.

Best regards,

grafxuser

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[Jon Nordby]

May I ask why you are not simply using GEGL as the backend for you
application? It implements a large number of image processing
operations (every one you've asked about so far) and is designed to be
reusable.


If there are issues which prevent you from using it we would love to
hear about it so we can improve the situation.

On 13/07/2012, Calculemus <[hidden email]> wrote:
> Nope I am far from releasing :)
>
> Why GIMP? It is the only open source for this kinda thing I know.
>
> Easy to find papers, hmm? Ok, I am a student and need your advice
> on this. Let's say I want to find a paper on an algorithm which I know
> what it does, and that is all. Where do I search? I am member at
> acm.org but usually they have very advanced papers.
>


--
Jon Nordby - www.jonnor.com
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[Calculemus]

So if I understand right, motion blur is just a convolution
with a mask?

For linear motion blur you create a line and maybe smooth it
a bit.

For zoom motion blur you need to calculate a different mask
for each pixel. So you need a line drawing algorithm to
create masks with lines rotated appropriately to face
the center of the zoom.

Not sure about radial blur.

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