An old plugin which still rocks

Image processing, astrometry, photometry, etc.
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Forum_2015
Posts: 358
Joined: 07 Dec 2018, 15:04

An old plugin which still rocks

Post by Forum_2015 »

In the last years I forgot that this plugin for Astroart 3:

http://www.princeton.edu/~rvdb/images/d ... econv.html

Still works very well on Astroart 5. The only minor problem is that on color images you will have to split the image in the R,G,B components.

About the other Richardson-Lucy algorithm (the one integrated in Astroart) remember that to prevent ringing you must bring the background value to near zero, with the command Offset, then Clip.
For example if the image has a background value of 1840:

1) Add Offset -1840
2) Clip Minimum 0 0 (to remove the negative pixels)

Or you may also the command Formula: IfHigher(v-1840, 0, v-1840, 0)

(The plugin does all that automatically)

Forum_2015
Posts: 358
Joined: 07 Dec 2018, 15:04

Re: An old plugin which still rocks

Post by Forum_2015 »

Some warnings:

1) The algorithm is very complex (so it's slow), on modern multi-megapixel images it will block the software for several minutes, and there is no progress bar.
2) The input image must have a maximum 16 bit range (0..65535 ADU). If your image is the result of a sum or it has negative pixel, you must Scale it to 16 bit, otherwise the plugin will calculate forever.

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