Star Colors after LRGBCombination

[Franky]

Hi Guys,

I have some issue with my star colors.

Background: When processing narrwoband SHO I remove all stars and process all images seperately from luminance. At the end of my work I combine the colored tonemap image with the luminance using LRRGCombination (after stretching, etc.).

Problem: Some of the stars are colored red, when the background nebula is also red (or blue if background ist blue). It seems to be get worse when using ChromianceNoiseReduction in LRGBCombination options... But for me this option is mandatory to get good looking colors without sprinkles in the nebula. I tried a lot, also for example removing the colors in tonemap image by using a star mask and then combine with luminace. Overall it's getting better - but not sufficient…

I added an example:

Left side (from top to bottom): Tonemap image; LRGB without ChromianceNoiseReduction; LRGB with ChromianceNoiseReduction
Right side (from top to bottom): Tonemap image with removed colors using a StarMask; LRGB without ChromianceNoiseReduction; LRGB with ChromianceNoiseReduction


Is there any idea, how to get rid of these colored stars?

Thanks
Frank

[aworonow]

you might try astro-imaging-insights.com > Methods > Annoying little red stars

Alex

[Franky]

Thanks Alex for your reply!

Read the article and tried it, but it's not working for me. Problem is, that also bigger sized stars are badly colored...

Any other ideas?

Thanks
Frank

[RickS]

Star mask and a reduce saturation curve?

[Franky]

Star mask and a reduce saturation curve?

Hi Rick,

that was of course my very first idea. Obviously I don't find the correct values for the Star Mask to get all these tiny stars.  Is there somewhere a known tutorial for that?

Frank