Sunday, September 13, 2015

Bringing out inner details in Pixinsight: HDRMultiscaleTransform vs. LocalHistogramEqualization

Recently, HDRMultiscaleTransform was introduced in Pixinsight (well, maybe not so recently, but I recently "discovered" it). I used it successfully a couple of times for images to bring out inner details in galaxies or nebulae. But a couple of times, it was way too strong. E.g. here is an image of M33 that I recently took (after most of the processing):

And here I applied HDRMultiscaleTransform (as "low" as possible):

That's WAY too much. Using a mask and using LocalHistogramEqualization:

I can play with the ContrasLimit setting and then with the Amount setting until I bring out just enough details in the galaxy core.