Author Topic: Maps Autostreched image integration etc  (Read 5500 times)

Offline mmirot

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Maps Autostreched image integration etc
« on: 2010 February 18 09:14:27 »


I think mapped information such as high/low reject for integration should be autostreched.
It would be a nice refinement and saves a step.
I don't think anyone processes these so why not optimise their visualization automatically?
 
It would be worth cloning the source images STF or a autostrech for other outputs deringing maps, color cal masks output etc.

Max

Offline Harry page

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Re: Maps Autostreched image integration etc
« Reply #1 on: 2010 February 18 10:10:29 »
Hi


I know what you are saying , but I find autostretch does not do a good job on these maps , perhapes a option to do so to keep us all happy  >:D


Harry
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Offline mmirot

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Re: Maps Autostreched image integration etc
« Reply #2 on: 2010 February 18 14:24:48 »
Are you using auto STF?

Max

Offline Niall Saunders

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Re: Maps Autostreched image integration etc
« Reply #3 on: 2010 February 18 23:40:14 »
I agree with Max.

Juan - perhaps we need two tick boxes next to the 'clip images' selection, to allow for inclusion of AutoSTF in the output stage.

Cheers,
Cheers,
Niall Saunders
Clinterty Observatories
Aberdeen, UK

Altair Astro GSO 10" f/8 Ritchey Chrétien CF OTA on EQ8 mount with homebrew 3D Balance and Pier
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Offline Juan Conejero

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Re: Maps Autostreched image integration etc
« Reply #4 on: 2010 February 19 03:23:59 »
Hi Max,

Quote
I don't think anyone processes these so why not optimise their visualization automatically?

Yes, these maps are very useful to process integrated images. In particular, you can use them to apply a wavelet-based noise reduction. The maps have values proportional to the number of rejected source pixels. Hence, where a map has a high value that means that your integrated image is noisier, as it integrates less images.

This is probably a unique case in astronomical image processing: we know exactly where the noise is, and we know its relative strength. The standard procedure is:

- Use PixelMath to create a mask with the maximum of the dark and bright rejection maps.

- Activate the mask for the integrated image.

- With the help of STF, apply ATrousWaveletTransform for noise reduction. For example, you can simply remove the first wavelet layer as a first approximation.

This procedure will compensate for the lack of SNR due to rejection. It is particularly efficient on rejected background areas. Note that wavelet transforms are linear, so your image won't lose linearity.

Quote
Juan - perhaps we need two tick boxes next to the 'clip images' selection, to allow for inclusion of AutoSTF in the output stage.

Agreed. I'll try to implement this feature in one of the upcoming versions.

Thanks for the suggestion.
Juan Conejero
PixInsight Development Team
http://pixinsight.com/

Offline Niall Saunders

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Re: Maps Autostreched image integration etc
« Reply #5 on: 2010 February 19 05:24:06 »
Thanks again Juan,

Another fine example of 'We ask, Juan explains' and 'We suggest, Juan accommodates'

Cheers,
Cheers,
Niall Saunders
Clinterty Observatories
Aberdeen, UK

Altair Astro GSO 10" f/8 Ritchey Chrétien CF OTA on EQ8 mount with homebrew 3D Balance and Pier
Moonfish ED80 APO & Celestron Omni XLT 120
QHY10 CCD & QHY5L-II Colour
9mm TS-OAG and Meade DSI-IIC

Offline mmirot

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Re: Maps Autostreched image integration etc
« Reply #6 on: 2010 February 19 06:45:11 »
Hi Max,

Quote
I don't think anyone processes these so why not optimise their visualization automatically?

Quote
Juan - perhaps we need two tick boxes next to the 'clip images' selection, to allow for inclusion of AutoSTF in the output stage.

Agreed. I'll try to implement this feature in one of the upcoming versions.

Thanks for the suggestion.


Great,

BTW, I think having auto STF apply and STF on-off buttons right on all image windows is still worth consideration.
It could change color when active like the red / blue button for RT preview
For simple out maps like these it would be just output in the active state.
A user could just click on it to turn off if the need these to back to STF inactive.

I know you don't want to clutter the image window options.
However, it is also quick way to see if a STF is applied and well as short cut.

Food for thought.

Max