RSS/Atom feed Twitter
Site is read-only, email is disabled

Why does a png file change colour when dropped as new layer?

2017-04-26 09:20:43 UTC (over 7 years ago)
postings
2

Why does a png file change colour when dropped as new layer?

I have 250 small png files that I want to set beside each other in a 25 by 10 matrix.

I open the first in gimp, then drop the others in from a file manager, or even open in gimp as new files, cut the indivual files and paste them as new layers in gimp.

In all cases I have tried the new files have their colours changed, or muted. Purples go to a grey, lime greens go to a muddy khaki, bright blues become muted.

I assume I have some setting incorrect, but do not even know what to google to find a solution. Can anyone help please?

Neil

rich2005
2017-04-26 10:37:41 UTC (over 7 years ago)

Why does a png file change colour when dropped as new layer?

I have 250 small png files that I want to set beside each other in a 25 by 10 matrix.

I open the first in gimp, then drop the others in from a file manager, or even open in gimp as new files, cut the indivual files and paste them as new layers in gimp.

In all cases I have tried the new files have their colours changed, or muted. Purples go to a grey, lime greens go to a muddy khaki, bright blues become muted.

I assume I have some setting incorrect, but do not even know what to google to find a solution. Can anyone help please?

Neil

All your images are in ***colour-indexed*** mode. Each image has its own limited colour palette (up to 256 colours). Copying one into the other forces the second (and more) to use the colour palette of the first.

Two alternatives:

1. The obvious, change all the images to RGB mode. Image -> Mode -> RGB ***before*** you drag/copy/paste

2. For your drag-n-drop-(n-wish) method ***set the first image*** to RGB mode as above, the subsequent indexed images will then be converted to RGB mode when you drag/copy/paste.

Note: the reverse is also true. Start with an indexed mode image, drag in a RGB image and the RGB image is forced to use the colours available from the indexed image.

rich: www.gimp-forum.net

2017-04-26 16:14:43 UTC (over 7 years ago)
postings
2

Why does a png file change colour when dropped as new layer?

Wow, how annoying. I've used gimp for years and never come across that.

Your solution is perfect, I dropped in all 200 images and the colours were as expected.

Thanks a lot, you saved me a ton of time.

Neil