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how can I change the existing values of color and alpha ?

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how can I change the existing values of color and alpha ? Cristian Secară 04 Dec 11:04
  how can I change the existing values of color and alpha ? Ofnuts 05 Dec 20:57
Cristian Secară
2013-12-04 11:04:08 UTC (almost 11 years ago)

how can I change the existing values of color and alpha ?

I have a plain rectangle with overall c09300c0 RGBA levels. I want to change the alpha channel value from c0 (193) to some other value, for the whole image at once. Or some other color channel.

How can I change the absolute value of a channel ? The color menu has only relative adjustments.

Thank you, Cristi

Cristian Secară
http://www.secarica.ro
Ofnuts
2013-12-05 20:57:20 UTC (almost 11 years ago)

how can I change the existing values of color and alpha ?

On 12/04/2013 12:04 PM, Cristian Secară wrote:

I have a plain rectangle with overall c09300c0 RGBA levels. I want to change the alpha channel value from c0 (193) to some other value, for the whole image at once. Or some other color channel.

How can I change the absolute value of a channel ? The color menu has only relative adjustments.

Thank you, Cristi

To change the alpha value, add a layer mask (initialize by transferring the layer's alpha channel), and bucket fill with the required value.

To change a color channel (say, red): use the Levels tool, select the red channel, and set it value to 0 everywhere by dragging white handle on the bottom scale fully to the right. Then add a layer, set it to "Addition" mode, and paint on it using colors with only a red component.