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Unsharp Mask Filter

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Has anyone succeeded to replicate Photoshop's Unsharp Mask and willing to share.

I'm trying to write an algorithm which uses it and I want to replicate it.

I encountered several Method, yet I'm not sure they are the same.


Edited by Drazick
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Actually I'm just prototyping something on Matlab.

If it works I could try write it for Paint.Net.

Hence I just need the basic Math behind it.

I saw many algorithms for USM, yet I need something similar to Phothsop / Gimp (With the Threshols Parameter).

If you remember, I asked you once in your blog if you could ever link between the two.


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OK, I managed to write something and it seems to work well.

If someone knows better to get results like Photoshop, Please let me know.

Here it is:

Input and Parameters (Just Like in Photoshop): A - Original Image, Amout, Radius, Threshold.

B - Blur image A using Gaussian Blur with Radius.

C - abs(A - B)

Mask = 1 Where Pixels of C > Threshold, 0 otherwise.

Output = A + Mask * (Amount * C)

That's it.

I hope it would work for you.

For anything that would make it more Photoshop / Gimp comparable, let me know.


Edited by Drazick
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