Noise reduction a 2nd time

[Rkonrad]

I tend to do a lot of work with stars removed from the foreground. I often wish I could do a second pass of noise reduction - especially if I had made some additions stretches. Some photoshop experts use an inverted mask to do their noise removal routine. Can that be achieved with startools? Actually knowledge of any other kind of noise removal at this point would be helpful

Cheers

[admin]

Hi,

The reason why StarTools only encourages a single pass is due to its Tracking data mining feature. A huge amount of data is collected on the propagation of noise at every turn. Unfortunately, going into another program will void that data as StarTools can no longer track the changes.

Luminance masks are crutches for programs that have no other means of using a moderating signal as a driver (so with luminance mask, brightness is used as a moderator).

That said, if you really need/want to use a luminance mask to modulate two images (for example a noise reduced image and a noisy image), you can use the Layer module - set the "Brightness Mask Mode" to the mode you require and vary the Brightness Mask Power as needed.

Hope this helps!

[Rkonrad]

HI Ivo

I always do a much work with tonal adjustments as possible before I denoise, then after the stars are healed I'm carefull (and hopeful) I don't have to do much more that would cause the image to become noisy again. Asides from the inverse mask, is there a better way to clean up noise if needed?

Richard

[admin]

Shot noise (the noise that we tend to primarily deal with) is made visible during non-linear stretching of the signal. That's why it is unexpected for noise reduction to be a necessity afterwards. That said, you can still use the Denoise module even with Tracking off. You just won't get the benefits of Tracking and the enhanced noise grain targeting that Tracking allows for.

Does this help?

[Rkonrad]

Thanks Ivo. For some reason, I thought denoising wasn't possible with tracking off.