Adjust colors

[Gerenuk]

I found a nice picture
http://mandelwerk.deviantart.com/gallery...8#/d2qg944
but I'd like to adjust the colors. To put it in words, I'd like to remove the greenish and the paleness. Now there are so many options and dimensions in Gimp, that I can't seem to find a systematic way to achieve a pleasing result.

Could you please suggest which adjustments I should try to make it less greenish, but rather yellow/red/brown and less pale?

[ofnuts]

Paleness is often a lack of saturation. See Colors/Hue-saturation

To change color, Hue-Saturation can also be used, or you can use Colors/Map/Rotate colors

[Gerenuk]

(Sep 5, 2011 16:06)ofnuts Wrote:  Paleness is often a lack of saturation. See Colors/Hue-saturation

To change color, Hue-Saturation can also be used, or you can use Colors/Map/Rotate colors

Will one of them (Hue?) screw up all colours together? I mean what if I'm just want to reduce one color (green; only accidently happening to be an RGB color) and leave the others more or less as they are?
I cannot simply replace this color since that would break the image as colours closeby wouldn't match.

[ofnuts]

Both methods let you pick the "range" of hue that is subject to change, but the "Rotate colors" tool gives you more control on that.

If you have a rather "narrow" color to change, you can also use "Colors/Color to Alpha" to make that Color transparent, and then insert under the layer another layer filled with the new color.

[Gerenuk]

Thanks for the good explanation!

Now I figured out that partly my discontent is due to the printed out version of this image, which comes out too dark in the darker areas. Is there anything I can do about it? I cannot adjust the printer so all I can do is to prepare the image in advance.

[ofnuts]

Having your printer print exactly what you see on the screen is called color calibration. Complex stuff, but worth it if you intend to print often.

You can light up the darks in the "Levels" dialog, just drag the middle handle to the left.

[Gerenuk]

(Sep 5, 2011 19:53)ofnuts Wrote:  Having your printer print exactly what you see on the screen is called color calibration. Complex stuff, but worth it if you intend to print often.

You can light up the darks in the "Levels" dialog, just drag the middle handle to the left.

So it's no "hardware problem" with the printer? If I turn up the darks this way it might look better or is the ink technique generally unable to reproduce some picture?

[ofnuts]

It's a complex matter of "color profiles". Your printer won't even give the same result if you change papers, for instance between plain paper and photo paper. In an ideal world you have calibrated your whole image chain and have a color profile for your display (redone every few months to compensate for display wear/aging) and one for every type of paper you use. Plus one for the scanner.

Adding to that is the concept of "gamut", ie the range of colors and tones your printer (and your display) can reproduce. Consumer-grade printers usually don't cover the whole sRGB color space.