Author Topic: WorkFlow Strategies (Stacking, Gradient Removals etc...)  (Read 4486 times)

Offline jerryyyyy

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I have been using PixInsight now for a couple weeks and trying to get a handle on it.  Ideally I would like to do all my processing on this one platform, but I am not quite there.

I seem to get better results stacking using CCDStacker than PixInsight... flats really seem to clean up images best in CDStacker  I can also produce a reasonable RGB image in CCDStacker.  However, CCDStacker does not have good gradient removal and PixInsight has DBE.  I have severe light polution and gradients with LRGD images seem to be a constant problem... they are limited but still require some processing. 

Moving images back and forth between the two platforms seems to require FITs 32-bit floating images... 32-bit integer made by CCDStacker does not seem to read into PixInsight.  It is not a pleasure. 

Do most users just bite the bullet at use PixInsight for all these processes, including stacking, or is there some clever way to move back and forthe seamlesslessly?
Takahashi 180ED
Astrophysics Mach1
SBIG STT-8300M and Nikon D800
PixInsight Maxim DL 6 CCDComander TheSkyX FocusMax

Offline topboxman

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Re: WorkFlow Strategies (Stacking, Gradient Removals etc...)
« Reply #1 on: 2013 April 11 09:41:46 »
There's nothing wrong with calibrating with another software. I use Nebulosity for calibration because it's quicker and cannot find any differences with PixInsight calibration. Saving Nebulosity's calibrated files in 32 bit floating point works fine with PixInsight. From then on it's all PixInsight processing starting with Star Alignment, Image Integration, RGB combination, and post processing.

Nebulosity cannot read PixInsight's FIT files. Unfortunately there don't seem to be a standard protocol for FIT.

Peter

Offline jerryyyyy

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Re: WorkFlow Strategies (Stacking, Gradient Removals etc...)
« Reply #2 on: 2013 April 11 11:55:41 »
There's nothing wrong with calibrating with another software. I use Nebulosity for calibration because it's quicker and cannot find any differences with PixInsight calibration. Saving Nebulosity's calibrated files in 32 bit floating point works fine with PixInsight. From then on it's all PixInsight processing starting with Star Alignment, Image Integration, RGB combination, and post processing.

Nebulosity cannot read PixInsight's FIT files. Unfortunately there don't seem to be a standard protocol for FIT.

Peter

Thanks.  Looks like I can register the RGBL separate stacked images in CCDStacker, then send them over to PixInsight for the DBE.  It appears the DBE must be done one each of the 4 components before stacking into a final image or you get a mess of different gradients.

Thanks for the sanity check on FITs foirmats....
Takahashi 180ED
Astrophysics Mach1
SBIG STT-8300M and Nikon D800
PixInsight Maxim DL 6 CCDComander TheSkyX FocusMax

Offline topboxman

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Re: WorkFlow Strategies (Stacking, Gradient Removals etc...)
« Reply #3 on: 2013 April 11 14:15:55 »
Just to be on the same page as you, do you actually combine LRGB right after stacking LRGB separately but before any kind of post processing? In other words do you combine LRGB while images are still linear (unstretched)? If so, I have seen several tutorials suggesting it's better to process L and RGB separately and do the LRGB combination later while LRGB components are non-linear. PixInsight tutorial says LRGB combination requires non-linear image components. Processing L and RGB should be as similiar as possible like same DBE samples and similar Histogram Transformation.

For DBE, personally I always run DBE after RGB combination instead running DBE on individual RGB components. PixInsight tutorial showed running DBE after RGB combination. I have seen others prefer running DBE on separate RGB components. Maybe I should try running DBE on separate RGB components to compare.

Peter

Offline jerryyyyy

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Re: WorkFlow Strategies (Stacking, Gradient Removals etc...)
« Reply #4 on: 2013 April 11 15:41:41 »
Just to be on the same page as you, do you actually combine LRGB right after stacking LRGB separately but before any kind of post processing? In other words do you combine LRGB while images are still linear (unstretched)? If so, I have seen several tutorials suggesting it's better to process L and RGB separately and do the LRGB combination later while LRGB components are non-linear. PixInsight tutorial says LRGB combination requires non-linear image components. Processing L and RGB should be as similiar as possible like same DBE samples and similar Histogram Transformation.

For DBE, personally I always run DBE after RGB combination instead running DBE on individual RGB components. PixInsight tutorial showed running DBE after RGB combination. I have seen others prefer running DBE on separate RGB components. Maybe I should try running DBE on separate RGB components to compare.

Peter

I am still inexperienced with this, but the images come out of CCDStacker I believe stretched as I do a "scaled" procedure with each prior to saving.  I have been unhappy with running DBE after combination since the gradients in the different RGB componets may do in different directions (it seems) so they are very hard to get out.  Whereas, If I flatten each component background first, they will not have this problem and the combo should be smoother (I hope).  This is the sequence if you do it all in CCDStacker and it works, but the problem is their version of DBE is not very good even on individual components. 

I think all the parts and pieces are the same, I am just trying to optimize the outcome by using the best components of each piece of software.  Stacking with PixInsight is a challenge for me.  Some subs just do not stack. 

Thanks for the help. 
Takahashi 180ED
Astrophysics Mach1
SBIG STT-8300M and Nikon D800
PixInsight Maxim DL 6 CCDComander TheSkyX FocusMax