Making Every Photon Count - Rosette Images Download

[Bonnylad]

I'm reading through this book for the second time, and took the author's suggestion to download from his site four zipped images of the Rosette nebula to manipulate and reconstitute (LRGB.)

Loading into Gimp (Linux), the images are all greyscale - all references to colour manipulation are greyed out. Adjusting all and every curve etc., just seems to alter contrast. They've been loaded singly, and as layers, but to no avail.

Should these images in fact be greyscale, is it an author error, or have I missed something (more likely)?

Cheers

 

[Cornelius Varley]

The images are in grey scale because each image represents the colour value of each channel of a lrgb image. Combined together the images will produce a colour image.

[Bonnylad]

Thanks for that. So loaded as four layers to start was correct?

[Cornelius Varley]

The image need to be pasted into separate channels (not layers). I assume gimp has channel mixing, which is the way it is done done in Photoshop.

[Bonnylad]

Thanks, Peter. I found a mode transform tab which rendered each image into RGB from greyscale. So playing from there.

Cheers.

[alacant]

Hi. That will only work if you drag each channel into a new layer and merge. The best way is to use the tool designed for rgb. It's in Colours > Components > Compose. Load each grey image into the rgb channels. HTH.

[ollypenrice]

Author error is most unlikely....

Olly

[Bonnylad]

Thanks, peeps. A lot further forwards.