LRGB Combination

[jblockyou]

I have been using PixInsight for a few months now and I am getting the hang of many functions but I'm having one problem with LRGB combination I can't figure out.
My first few sets of LRGB images I took through the scope were all binned 1x1 and I had no problem processing them. Last night I took a sequence of images and I exposed the Luminance using 1x1 binning. The RGB images were each binned 2x2. I wanted to try this to cut down on imaging time. The problem I am having is when I try to combine my processed Luminance image with the RGB image I get no color whatsoever. I resampled each RGB image to match the same pixel size as the Luminance and then combined them to make the final RGB color image. This combined image has plenty of color. I just can't get any color when I combine the Luminance with the RGB. Does taking the RGB images binned at 2x2 reduce the color? or is there something I'm missing?
Thanks for any suggestions.
John
 

[pfile]

are the RGB and L images already stretched? what method are you using to combine them?

rob

[vicent_peris]

Hi John,

Seems like your RGB image is not stretched.


Best regards,
Vicent.

[jblockyou]

I'm using the LRGB Combination Tool as I have used several times before. Both images have been stretched and processed like I usually do.

[jerryyyyy]

Another way to check what is going on is to use the AIP LRVP script under Image Integration.  I believe this does the integration in a slightly different manner possibly with a couple masks along the way. 

BTW, since all the gurus seem to be commenting on this, can I ask the question about what is the best sequence to do:

Linear Fit
DBE
and RGB integration. 

In my business, this is known as a "non-directive question". 

[pfile]

perhaps then you need to fiddle with the saturation transfer function. smaller values mean more saturation. try that out

rob

[Dimitris Platis]

Would u mind publishing some data on that?
For example some statistics on the average luminance values of L and RGB images....
and perhaps some info on how exactly u r using the LRGB tool....

[jerryyyyy]

I think it varies with the image.  Preface, I am not an expert.  But in general with my set up I have the L at 60 and the RGB at 35, but often I will try variants and have gone down to 20 on the RGB (If there is any color 20 will find it).  You can also afterwards crank up the saturation with Curves Transfer.

I believe, but am not sure, that if you have a blurred RGB image you must use the LRGB function to add the L by dragging the L into the RGB image.  I am not sure the AIG script does that.   

[jkmorse]

John,

One thing to consider is the whether your lum and the L component of your RGB match before you combine.  The easiest way to do that is to use ChannelExtraction with the Lab setting.  Apply that to your RGB to get the three subframes.  Open your Lum, then open Linear Fit and make the Lum your reference image.  Apply the tool to the L component, then recombine the L, a, and b components using Channel Combination.

Hope that helps,

Jim