New Filter: Constrained Sharpen


I have added a new sharpening filter to my testing folder.

It sharpens the image but restricts sharpening to local min/max to reduce halos. It is particularly good for upsized images and artwork.


WOW, looks good

(Alan Gibson) #3

Great minds think alike.

I’ve also implemented sharpening (or any operation) with output limited to the range of a local area of the input. This sharpens without overshoot.

A related operation sets every pixel value to either the minimum or the maximum of the local area.

These processes don’t overshoot, so they cannot cause clipping.

Details at Limit min-max


Limited USM:

Set L channel of LAB to min or max:

(Lyle Kroll) #4

May give it a try on my next edit, Iain. You do make great presets and am thankful for that. :slight_smile:


Or ‘simple minds seldom differ’ :wink:

Cheers. It’s good to know people are using my stuff.

(Melissa Newcomer) #6

That is an interesting filter. How can I use it? Not real good at GIMP.


It is part of the GMIC plugin. Are you familiar with that?