Quote:
Originally Posted by Ingo
Where does the red green and blue come from? I put them in photoshop, layed them on top of eachother, and there were no colors?
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Ingo, the way I did it (which might be the long way round) is as follows:
Turn each of the JPEGs (which are 16-bit greyscale images) into RGB.
Note: I use Photoshop CS2 which handles 16-bit images, earlier versions handle these in varying ways … you may need to turn the originals into 8-bit greyscale and then into 8-bit RGB, thus losing a great deal of the tonal range.
For the blue one, add a new layer and fill it with solid blue R=000 G=000 B=255
Change the filled layer from ‘Normal’ to “Multiply’.
Flatten the image. You now have the ‘blue’ image.
Do a similar operation to the green and red images, using R=000 G=255 B=000 and R=255 G=000 B=000 respectively.
Copy and paste the green and red images onto the blue (background) image to give a three-layer file. (You can drag and drop between files, thus avoiding the clipboard, but then you may have alignment issues.)
Turn layer 1 (green) and layer 2 (red) from ‘Normal’ to ‘Difference’.
Voila … a vaguely-coloured image.
You can then muck about with the individual layers (saturation, etc.) to see what effect it has on the displayed image. I did this to at least make the ‘whites’ white. If you flatten the image, you can do the overall levels, saturation, etc.
Trouble is, it’s a lot of work to produce - at least in my case - a final image inferior to the astro processing s/ware used in the other posts (not to mention the knowledge and experience that goes into tweaking the red, green and blue images along the way).
I assume the result I obtained is more-or-less the best one can do using PhotoShop alone.