How do you remove stars from image?

[topboxman]

How do you remove stars from image? I am sure star mask is used to do this, then what?

Thanks,
Peter

[MortenBalling]

I'm new to PixInsight, and I don't know, if it can be done using that, but Metsavainio has made an Action for Photoshop, that can do the trick:

http://astroanarchy.blogspot.dk/search/label/PS-actions

Best regards

Morten 

[topboxman]

Thanks Morten but I don't have Photoshop.

Peter

[topboxman]

Never mind. I don't need to remove stars from a image.

Thanks,
Peter

[naavis]

A similar method to the Metsävainio one can be used in PixInsight. First you need to make a star mask, and the apply the MorphologicalTransformation tool iteratively using Morphological selection as the operator. Once in a while you may need to redo the star mask and continue iterating the MT tool.

[marekc]

I'd love to see an example of this. It would be great to see the different iterations, as the stars slowly shrink away, as well as any changes in the StarMask settings that become necessary during the shrinking. An `after' version of the image would be interesting to see too, as well as a `stars only' image, if that can be generated via PixelMath.

[martin_magnan]

Here is an example

http://blog.deepskycolors.com/archive/2011/09/08/star-size-reduction-via-Morphological-.html

just repeat until there is no stars

Martin

[georg.viehoever]

Here is an idea that I have not yet heard elsewhere: Use GradientMergeMosaic to make stars disappear. The idea probably needs some polishing, but a quick experiment shows nice results:

- Use StarMask to create a StarMask (in the example: binary starmask) from original.
- Use PixelMath to stamp out the stars from original. Save image to disk.
- Change StarMask to float with FormatConversion and to RGB using ConvertToRGB. Save image to disk
- Use GradientMergeMosaic to merge the the stamped out image with the star mask

In screenshot 1 you see the original (top left), starMask (bottom left), stamped out stars (bottom right), merged result (top right). Screenshot 2 shows the settings for PixelMath and GradientMergeMosaic.

Georg

[chris_todd]

Here is an idea that I have not yet heard elsewhere: Use GradientMergeMosaic to make stars disappear. The idea probably needs some polishing, but a quick experiment shows nice results:

Man, that's clever!  I'm going to have to try that.