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OSC cameras & LRGB

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#1 pyrasanth

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Posted 25 February 2020 - 09:16 AM

Is there any point in pulling out the L channel from an OSC camera & processing that data separately?

 

I've often pondered this- will it make any difference- is the L channel not a part of the RGB data you've just captured or is there going to be a difference. The L channel may help with defining colour saturation but are we going to get any more detail?

 

Your thoughts please!

 

Best wishes

Mark

 



#2 crgood2

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Posted 25 February 2020 - 09:46 AM

I think it depends on how you process the images.  I will frequently pull a synthetic L from OSC data for deconvolution and a bit linear noise reduction.  If the chrominance data is especially noisy, I'll also do linear noise reduction on the color image.  Then when the LRGB is recombined in PixInsight, you get the benefit of the chrominance noise reduction here as well.  I feel I get better results this way than processing the OSC data by itself.  



#3 pyrasanth

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Posted 25 February 2020 - 09:55 AM

I think it depends on how you process the images.  I will frequently pull a synthetic L from OSC data for deconvolution and a bit linear noise reduction.  If the chrominance data is especially noisy, I'll also do linear noise reduction on the color image.  Then when the LRGB is recombined in PixInsight, you get the benefit of the chrominance noise reduction here as well.  I feel I get better results this way than processing the OSC data by itself.  

I process my OSC data in the same way as yourself & I've never just left an OSC RGB image by itself without processing & adding L data. I wondered with a bit more tweaking of the RGB alone whether I could get the same image quality.

 

I see all the advantages given by PI processing & chrominance noise reduction etc but I wonder if it is worth the effort as mostly my images from OSC are pretty rubbish anyway!


Edited by pyrasanth, 25 February 2020 - 09:57 AM.

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#4 crgood2

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Posted 25 February 2020 - 09:57 AM

I agree there are probably other ways to enhance the OSC data, but like you, I don't put too much work into the OSC, lol.  


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#5 bobzeq25

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Posted 25 February 2020 - 10:42 AM

Is there any point in pulling out the L channel from an OSC camera & processing that data separately?

 

I've often pondered this- will it make any difference- is the L channel not a part of the RGB data you've just captured or is there going to be a difference. The L channel may help with defining colour saturation but are we going to get any more detail?

 

Your thoughts please!

 

Best wishes

Mark

There are advantages in having two processing streams.  Because of the characteristics of our eyes, L (which our eyes use to see detail) can use more sharpness, RGB can be blurred a bit to remove noise.  In practice, few people actually do it.  Likely related to the fact that most (not all) OSC users are either beginners, or seek less complication.


Edited by bobzeq25, 25 February 2020 - 10:45 AM.


#6 bmhjr

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Posted 25 February 2020 - 10:56 AM

Likely related to the fact that most (not all) OSC users are either beginners, or seek less complication.

lol.gif   Or maybe because OSC users have found the processes in Pixinsight can be selective in their application to only the L channel or Chrominance channel as needed.


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#7 euthus

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Posted 25 February 2020 - 12:51 PM

I'm interested in pulling out the L and RBG from OSC for processing.  I've looked for tutorials on processing OSC images this way (I'm using PixInsight and relatively new to the game) but I can't find one that explains the nuts and bolts (I'm sure there are tutorials out there but can't find one).  So my question is, at what step do you split out L and RGB to do the separate processing?  For example - use the integrated file (just before postprocessing) or right at the beginning (split out each sub)?

 

Thanks

Eric



#8 bobzeq25

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Posted 25 February 2020 - 02:13 PM

I'm interested in pulling out the L and RBG from OSC for processing.  I've looked for tutorials on processing OSC images this way (I'm using PixInsight and relatively new to the game) but I can't find one that explains the nuts and bolts (I'm sure there are tutorials out there but can't find one).  So my question is, at what step do you split out L and RGB to do the separate processing?  For example - use the integrated file (just before postprocessing) or right at the beginning (split out each sub)?

 

Thanks

Eric

Easy, although like everything in PI, obscure.  ChannelExtraction and ChannelCombination.  Some stuff is on the default top bar, but all can be done off the menus.  The wrinkle is the (6?) choices in color space.

 

Generally it's done after calibration and stacking, I'm sure you can find all kinds of workflows.  Part of the challenge involved in using PI to it's maximum capability, and likely user, setup, and target specific.

 

There's no cookbook.  There are a number of competing cookbooks.  <smile>  I think this guy is the best guide to developing your own workflows for L and RGB.

 

https://www.amazon.c.../dp/1138055360/

 

A fine example of how the $250 financial cost of PI pales in comparison to the time spent learning how to use it.


Edited by bobzeq25, 25 February 2020 - 02:20 PM.

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#9 euthus

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Posted 25 February 2020 - 03:10 PM

Thanks!  One more thing to add to my growing and growing list of processes to learn and play around with.


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#10 crgood2

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Posted 25 February 2020 - 05:35 PM

I'm interested in pulling out the L and RBG from OSC for processing.  I've looked for tutorials on processing OSC images this way (I'm using PixInsight and relatively new to the game) but I can't find one that explains the nuts and bolts (I'm sure there are tutorials out there but can't find one).  So my question is, at what step do you split out L and RGB to do the separate processing?  For example - use the integrated file (just before postprocessing) or right at the beginning (split out each sub)?

 

Thanks

Eric

Eric,

 

I typically pull a synthetic luminance after channel combination and DBE.  It's part of the channel extraction tool, there's also a button that on the toolbar for extracting the CIE *L component.  




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