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Artifacts from AutoStakkert drizzle

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#1 Jairo

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Posted 03 August 2014 - 08:14 PM

Hi!

 

I notice some artifacts that appear near high contrast areas, when I use the drizzling function from AutoStakkert 2.2.0.12. They seem to become strongly pixelated with the slightest sharpening. I don't know if it's a normal feature of the drizzling algorithm, or if I'm doing something wrong. I never got this from RegiStax's drizzle; bad results could be blurry, but never with these artifacts.
 

I annexed an example, which received a gaussian sharpening level around 50 in the first layer in RegiStax. Could you help me?

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#2 *skyguy*

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Posted 05 August 2014 - 08:20 AM

I've never used AutoStakkert ... however, I do use Registax and other image processing programs that include the Drizzle algorithm and I do use Drizzle on a regular basis. You need a large number of sub-frames and they must be dithered for Drizzle to work correctly. If you don't meet this criteria ... you can end up with "holes" in the final image ... and I believe that is what you're seeing in your image. One solution to this problem is not to aggressively up-sample images . Take a look at this article written by Craig Stark that explains how Drizzle works:

 

http://www.stark-lab...Drizzle_API.pdf

 

 

 

 



#3 CharlesW

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Posted 05 August 2014 - 09:21 AM

You'll get the most help with your question over in the Solar System imaging area. Some of the best in the world live there. 



#4 Jairo

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Posted 05 August 2014 - 09:09 PM

Thank you all, I'll ask there.

 

I agree it's like the "hole in the image" effect, but the image was so poorly tracked that it's guaranteed it got enough dithering.

 

And I used 1500 frames. Can using too much be a problem too, for drizzling?




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