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Set saturation and value for all pixels collectively [SOLVED] - Printable Version

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Set saturation and value for all pixels collectively [SOLVED] - akgimp - 04-20-2017

Hello, Looks like a lively and positive forum, glad to find it.

How to set the saturation for all pixels to 100%? Likewise for value. I'm leaving hue alone.

The hue-saturation tool does not do this, as far as I can see. My evidence is this: create a new image any size, fill it entirely with hsv 215,20,45. In the color tool, use the color picker to select anywhere, which puts this color into the color tool's swatch. Slide the saturation and value to 100 each. Then in the hue-saturation tool, increase saturation and value (called lightness here) to maximum each. Compare the image with the swatch.


RE: Set saturation and value for all pixels collectively - Ofnuts - 04-20-2017

Use specific layer blend modes (selector at the top of the Layers list). Upi likely want two layers, one for value and one for saturation. Or look at the problem from the other side, and use your exiting layer in "Hue" mode over a uniform layer filled with a color which is 100% saturation and 100% value.


RE: Set saturation and value for all pixels collectively - rich2005 - 04-20-2017

Ofnuts is a better answer, My answer FWIW

@akgimp
You are not comparing like-with-like. The scales are different 0-100 v -100 <> +100

Trying your image HSV 215,20,45 Looks like this: http://i.imgur.com/RZzlAFg.jpg

Decompose that: Colors -> Components -> Decompose (into layers): http://i.imgur.com/6IYMobf.jpg

Fill the saturation and value layers with white (RGB 255,255,255 = 100%) : http://i.imgur.com/an7WejM.jpg

Recompose that: Colors -> Components > Recompose gives this: http://i.imgur.com/4CunaLQ.jpg

Do you have a specific purpose for this? Someone might come up with better advice.

edit: If you are using specific images and you need to set 100% saturation and value have a look at the gmic plugin http://www.gmic.eu which has interactive color curves, you can drag a curve up to give 100% and have a real time display of the effect.


RE: Set saturation and value for all pixels collectively - akgimp - 04-20-2017

Wow, superb replies, and fast! I agree rich2005 that that ofnuts reply is easier to implement, but your method offers insights into color and how gimp works, which I found very informative. Both great answers, thanks fellas. I'll try to mark this solved if permitted.

The purpose, BTW, is analysis for mixing paints, but no need to go into that here, I've got my answer.