Partial gamma correction

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Partial gamma correction

Post by cjanice » 2018-09-20T01:04:59-07:00

I have a RGB image and I would like to select the first n% of red, green and blue for gamma correction while leaving the other pixels unchanged.

How can I do it in ImageMagick with version 6.7.8-9 on Linux?

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Re: Partial gamma correction

Post by snibgo » 2018-09-20T03:35:50-07:00

I don't understand the question.

A required operation often breaks down into:
- what changes do I want?
- where do I want those changes?

A solution is to clone the input, apply the changes to that clone, then composite the clone over the original using a mask that is white where we want the changes and black where we don't.

For your problem, the mask might come from "select the first n% of red, green and blue" but I don't know what that means.
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