Switching on the Auto Color Noise Reduction adds red to the background and with the added red I can't tell if it's causing any improvement to the stacked image.
Don
Auto Color Noise Reduction
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Re: Auto Color Noise Reduction
Hi Don,
hmm, I wasn't expecting that, but I can see what you mean - a hint of a red colour cast and if you watch the histogram on the right, the red curve moves a bit to the right when the colour noise reduction is turned on.
The bad news is I can't see how/why it would happen. Colour noise reduction is quite simple, turn the image from RGB into Lab (Luminance-A-B colour space), smooth the a and b components then convert back. I wonder if the fact that the RGB<->Lab conversion is non-linear is the issue (combined with the smoothing).
I could try HSV instead of Lab, but I think that would give poorer results generally.
interesing!
Robin
hmm, I wasn't expecting that, but I can see what you mean - a hint of a red colour cast and if you watch the histogram on the right, the red curve moves a bit to the right when the colour noise reduction is turned on.
The bad news is I can't see how/why it would happen. Colour noise reduction is quite simple, turn the image from RGB into Lab (Luminance-A-B colour space), smooth the a and b components then convert back. I wonder if the fact that the RGB<->Lab conversion is non-linear is the issue (combined with the smoothing).
I could try HSV instead of Lab, but I think that would give poorer results generally.
interesing!
Robin