Differential Adaptive Noise filter ?

[terrym2002uk]

Hi,

Could you explain how this new feature works and how you would apply it?

Cheers

[admin]

Hi Terry,

The Differential Adaptive Noise filter in the Layer module measures the difference in brightness for each pixel and based on that difference, applies an amount of noise reduction to that pixel. Its goal is to suppress noise that was induced by any image brightening by any module.

Here is an example of its use;
Load an image that looks nice, but is a bit dark. Put it through the Development module to brighten it up.
Now launch the layer module. Click Undo->Bg (this should put the image as it was before it was brightened into the background layer). Now select the Differential Adaptive Noise filter as the Foreground Filter.
If you now compare the foreground with the composite, you should see the a reduction in noise in the areas that have brightened the most. Sometimes the effect can be subtle, sometimes there isn't enough 'differential' for the filter to kick in; your mileage may vary but it can sometimes enable you to stretch data that little bit further without noise becoming (too) obvious.

Yes, I need to document all this

[terrym2002uk]

Thanks Ivo. I'll give it a try.