Re: [APML] Another image processing challenge for snowy nights-M45

["Franklin Holub" <lists@my-spot.com>]

O.K. Here is my shot at it. This was a bit more challanging then the rosetta. The sky fog 
really was a pain to deal with...

http://www.my-spot.com/images/m45small1.jpg

Here were the steps (BTW everything was done in Picture Window 2.5)

1. Convert to 48 bit
2. Crop and rotate 180° so the view is in a more familiar orientation. This also chops 
off the vinetting so the background is easier to fix with curves.
3. Adjust contrast with curves in RGB color space
4. Extract Red Green & Blue channels.
5. Guassian Blurr the blue channel (BC). Radius 5, Thresh 255.
6. Apply curves to the blurred BC. Make the background nearly black and use the 9x9 probe 
to ramp the blue reflection nebula to the level I like. Be carefull to not overcook the 
stars.
7. Composite the original BC and the "curved & blurred" BC with the subtractive Filter.
8. Go back and mildly adjust the curves of the RC & GC to roughly match the new BC.
9. Recombine the BC from step 7 and RC and GC from step 8
10. One final tweak of the curves in HSV color space and we are done.
11. A fix of any color shifts that may result can be done in color > curves using Hue (H) 
channel in HSV or HSL color space.
12. Save the 48 bit image as a tif.
13. Resize to 768 x 512 (that just the size I like).
14. Convert to Color (24 bit).
15. Save as a jpeg.










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