How to begin with CFA images

Tom Shaull

This may be a silly question but ...

I have a SBIG ST-2000XCM single shot color camera. What is the recommended approach to processing these single shot color images? I create the standard bias, dark and flat field images. I currently process using the Batch PreProcessing script to calibrate, debayer and combine the CFA images and the result is a single RGB image. I use this RGB image as my starting point for further processing. Is there a better way to do this initial processing?

I notice that all of the images processed in the PI Fundamentals series appear to be classic LRGB images. I think it might be useful to touch on CFA image processing at the beginning of the Fundamentals series.

BlockHead

It sounds like you are doing exactly the right thing- great job.

From the combined RGB, likely the next thing to do would be to extract the luminance from it and

work on this luminance file taking the same "classic" route an LRGB travels. It does depend somewhat on the data. For example, if you are not going to be using deconvolution- extracting the luminance may not be quite as critical.

I agree, I need to make a section on this I hope that during this upcoming "break" before the New Year I can produce a few more lessons.

-the Blockhead 

BlockHead

Hi Tom,

Happy New Year. As you know, I published the OSC section... so you can review that now.

After looking as deeply as I can, I see no significant differences in processing other than issues that concern the initial handling of the matrix itself. My style has always been to take two routes for luminance and chrominance images- even if they started their lives in an original RGB image. So I view the "classic" handling- as "standard" for OSC or filtered data sets. I think this has to due with the fact that the best contrast of color and detail is attained by managing how the luminance blends with the RGB data. When these channels are together... it is more difficult.

-the Blockhead

Tom Shaull

Wow, It took me awhile to get back to you. My primary concern was with how I used Batch PreProcessing with my OSC raw images. I agree with you that after the initial integration and generation of a luminance image there would be little difference from your standard processing flow. It was good to hear that I was already doing it properly and I am going to add the luminance generation to my processing flow going forward.

Tom S..