remove motion blur

[NotMyFault]

Hi,

 

anybody aware of a method to remove motion blur in Affinity?

Having an image of night sky with star trails of e.g. 7px length resulting from long exposure, assuming all are perfectly parallel and in the same angle. Every star (of 1-2px light color) is stretched over 7px, and clearly different from much darker sky.

 

My idea would be to replace any 7px trail by the 1px having the sum of all light pixels (3 to the right and left, custom filter), and letting the dark background untouched (fill in 3px to every side of trail with average of background pixels, similar to inpatient or dust & scratch removal).

[d_jan]

What you describe is similar to an approach called "Deconvolution". As far as I am concerned it is not implemented in Affinity. Smart Deblur has a motion blur deconvolution (I have no experiences with it).
You can find implementations of deconvolution in RawTherapee and gmic (plugin collection that also works in Affinity Photo) but as far as I am concerned these can only be applied to circular blurs, not to motion blurs. In general, you are very quickly in advanced math space with deblurring.

Edited May 31, 2022 by d_jan
clarification

[Old Bruce]

Just now, d_jan said:

these can only be applied to circular blurs

But are star trails not circular? The pole may be out of frame but they would be curved.

Regardless, I expect the use of much heavy math(s).

[NotMyFault]

30 minutes ago, Old Bruce said:

But are star trails not circular? The pole may be out of frame but they would be curved.

Regardless, I expect the use of much heavy math(s).

Yes in general. But depending on some factors like focal length / field of view, exposure time etc, you might use linear as approximation to simplify.

[NotMyFault]

35 minutes ago, d_jan said:

What you describe is similar to an approach called "Deconvolution". As far as I am concerned it is not implemented in Affinity. Smart Deblur has a motion blur deconvolution (I have no experiences with it).
You can find implementations of deconvolution in RawTherapee and gmic (plugin collection that also works in Affinity Photo) but as far as I am concerned these can only be applied to circular blurs, not to motion blurs. In general, you are very quickly in advanced math space with deblurring.

I experimented a bit with gmic (when on Windows), need to re-install again on M1 Mac where should be available now.

[thomaso]

You could try "Topaz Sharpen AI" ($ 79)  https://www.topazlabs.com/sharpen-ai

It has the "Stabilize" function to remove motion blur. Here in action from 10:50 min …

 

[NotMyFault]

Thanks for all your replies. I don't intend spending extra money or using other apps, just curious if this is possible with any kind of workflow directly in Affinity. 
 

[thomaso]

16 minutes ago, NotMyFault said:

any

Of course it is! For instance ...

   🤓😇

[Lisbon]

19 hours ago, NotMyFault said:

anybody aware of a method to remove motion blur in Affinity?

Probably one of the most difficult problems to fix.

One method you can try is using the Emboss filter (Filters > Colours > Emboss) in soft light and try to shift the pixels in a direction opposite to the motion blur.
If you start with a little motion blur, you might be able to see some improvement.

And then there are the deconvolution algorithms.
There is a free software called "Image Analizer" for windows that you can try.
Unfortunately there is not enough information on how to use this "Restoration by deconvolution" filter and requires some processing power to estimate the parameters.

Ive never used Topaz Sharpen Ai, but based on the examples Ive seen so far, Id say its the best method to fix motion blur problems.

[user_0815]

On 5/31/2022 at 11:05 PM, NotMyFault said:

Thanks for all your replies. I don't intend spending extra money or using other apps, just curious if this is possible with any kind of workflow directly in Affinity. 
 

Just had the same question. Then I remembered that there is a sharpening technique using blur. After trying around a bit, it seems that using the motion blur filter for sharpening can be used to undo motion blur in the photo at least a little bit. Instead of using regular blur, use motion blur in the direction and distance of the unwanted motion blur.