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Help with colour matching problem and 'colorize'

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Help with colour matching problem and 'colorize' Daniel Kasak 28 Mar 05:54
  Help with colour matching problem and 'colorize' John R. Culleton 28 Mar 23:03
Daniel Kasak
2006-03-28 05:54:05 UTC (about 18 years ago)

Help with colour matching problem and 'colorize'

Greetings.

I'm a casual Gimp user. I have to make a brochure front-cover thing, consisting of a collection of existing images. I'm having trouble with colours.

One particular image ( which is mostly blue, and is a large JPEG file ) copies and pastes correctly into a new image. When I print it, however, it turns quite cyan. I thought this might just be my printer drivers or something ( Epson R1800 with the latest gutenprint / gimpprint drivers ), but then I noticed something very interesting.

When I select the layer with the blue image, right-click, and select:

Layer ==> Colors ==> Colorize ...

the blue image turns the *exact* colour that it turns out when printed - cyan. I've tried playing with the 'Hue' and 'Lightness' sliders. I can sort-of get a colour similar to the original, but not really. If I click 'Cancel', the colour returns to the original colour.

What's going on ( specifically, why does the blue layer change colours the moment I open the 'colorize' dialog, and is this related to the colour of the final print ), and is my colour matching problem something I'm doing wrong / something I can fix?

Thanks :)

Dan

John R. Culleton
2006-03-28 23:03:59 UTC (about 18 years ago)

Help with colour matching problem and 'colorize'

On Monday 27 March 2006 22:54, Daniel Kasak wrote:

Greetings.

I'm a casual Gimp user. I have to make a brochure front-cover thing, consisting of a collection of existing images. I'm having trouble with colours.

One particular image ( which is mostly blue, and is a large JPEG file ) copies and pastes correctly into a new image. When I print it, however, it turns quite cyan. I thought this might just be my printer drivers or something ( Epson R1800 with the latest gutenprint / gimpprint drivers ), but then I noticed something very interesting.

When I select the layer with the blue image, right-click, and select:

Layer ==> Colors ==> Colorize ...

the blue image turns the *exact* colour that it turns out when printed - cyan. I've tried playing with the 'Hue' and 'Lightness' sliders. I can sort-of get a colour similar to the original, but not really. If I click 'Cancel', the colour returns to the original colour.

What's going on ( specifically, why does the blue layer change colours the moment I open the 'colorize' dialog, and is this related to the colour of the final print ), and is my colour matching problem something I'm doing wrong / something I can fix?

Thanks :)

Dan

Gimp works in the RGB color model and printers use the CMYK color model. CMYK cannot recreate all the shades available with RGB. The programmers of Gimp are working on the problem but they aren't there yet.

Some tools that work in the CMYK model are Scribus and the crash-prone Krita. For your brochure task I would try Scribus. Don't expect the range of filters etc. found in Gimp but for creation of a brochure, and seeing which colors work I would go for it. There is a function in Scribus that checks for out of gamut colors in e.g., a photo and colors them green so you can evaluate the impact.