isolated black dots after MMT

[Buzz]

I'm a bit puzzled. I'm using MMT on a non linear narrowband image for noise reduction. The noise reduction is being applied progressively across the four first scales as per normal practice. After application, I have isolated dark pixels peppering the image, even in regions of bright nebulosity.

These diminish if I reduce the bias of the first scale and altogether if I disable the first scale. I'm surprised that the noise reduction does not remove them. Any ideas? I'm using the latest version of PI but I don't think the issue is isolated to this version.

[Juan Conejero]

Those dark pixels are outliers. Increase the adaptive noise reduction parameter to get rid of them. Also, applying sharpening and noise reduction simultaneously in a single instance of MMT (that is, increasing a layer bias and enabling noise reduction at the same time) can be tricky, especially for linear images.