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Comment by MOARDONGZPLZ | Hacker News Reader

Is there a typical number of radius pixels people use? I'm not a photographer, so I can't really say.

Below 10px, your tool is the worst, from 10-30px, GIMP is awful, Photoshop is the best. Above 30px, your tool is the best. However, Photoshop doesn't seem to fall too far behind in actual seconds even as you approach 100px.

So do photo editing people typically use a smaller radius or larger radius, or does it just depend?

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Below 10px radius, all programs take under 0.5 seconds, so you don't even notice the difference.

The picture in an example was made with a radius about 12px. But Photoshop and GIMP allow larger radii, so I think large radii are used sometimes, too.

BTW. it really surprised me, that Adobe Photoshop uses such a simple algorithm, while faster (and slightly more complex) algorithms exist for quite a long time.

I guess it depends on the resolution. To remove a given scratch of a given absolute size in cm, if your photo has twice the resolution you will need twice the pixels so twice the pixel size.

Twice the resolution is 4 times the pixels, no?

Yes, but twice the radius (in pixels) Is also four times the (affected) pixels.

I don't do photo work; but, I went and played with the tool and, at least for the photo provided, anything above 10px really started taking the photo into the "Uncanny Valley" territory.

As someone else pointed out - the radius is relative to the resolution. 10px is nothing when you're working at high DPI.

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