LibRaw implementation of digital camera raw format decoding

[dchamberlain]

Hi,

I'm trying to understand the Libraw camera raw decoder and how I should have it set up for images taken with my Canon 6D DSLR camera.

When I installed the decoder, it was making everything monochrome. I went into the settings and saw where Pure Raw was checking "Create raw CFA image". I unchecked it and checked "Create raw RGB image" thinking that would allow the color information to come through. But now my images are really, really dark, even when autostretched.

What should I have the decoder settings at for my camera?

Thanks

Dale

[bulrichl]

Hi Dale,

it depends on what you want to do.

If you want to see the raw CFA (monochrome) "image", choose 'Pure Raw' and set 'Create raw CFA image'. If you want to see a RGB image, choose 'Demosaiced RGB' and set the desired interpolation method.

The preprocessing of astro images shall be done with monochrome CFA images. Only after full calibration, and before ImageRegistration (StarAlignment), the CFA images have to be debayered.

With daylight images you don't need to perform processing steps on CFA images.

With the processes that can work with raw data, you have the possibility to overrule the general settings in the DSLR_RAW or RAW module, namely by input hints (see https://pixinsight.com/forum/index.php?topic=9559.0 ). It is convenient to set 'Demosaiced RGB' and use the input hint 'cfa' in processes like ImageCalibration or ImageIntegration, if you want to process both daylight and astro images with PixInsight.

Hope this helps.

Bernd

[dchamberlain]

Thanks Bernd,

I'm still learning about the processes and what is actually happening. So if I understand correctly, even though I capture CR2 files with color information in them, they are calibrated as monochrome CFA images. That says to me that the bias, darks and flats should be processed the same way. Then before taking them through StarAlignment they must be debayered in order to restore the color elements?

Again thanks,

Dale

[bulrichl]

So if I understand correctly, even though I capture CR2 files with color information in them, they are calibrated as monochrome CFA images. That says to me that the bias, darks and flats should be processed the same way. Then before taking them through StarAlignment they must be debayered in order to restore the color elements?

Yes, that's right.

Bernd

[dchamberlain]

Thanks again Bernd!

I made it through and got an amazing image!