Copy link to clipboard
Copied
I'm looking to use the DNG SDK to write DNG files from quad bayer RAW image data but I'm not sure if DNG actually supports this bayer pattern.
I have found DNG sample files from cameras which use quad bayer sensors but analysing the DNG/TIFF tags they're not correctly reporting a quad bayer pattern.
Does anyone know if DNG actually properly supports quad bayer?
Copy link to clipboard
Copied
Some more detail would be helpful here - what do you mean by "not correctly reporting a quad bayer pattern"? Quad bayer is just a 16 pixel bayer pattern.
Copy link to clipboard
Copied
I have a couple of sample DNGs from the DJI Mavic Air 2 which features a 48mp quad bayer sensor. At 48 megapixels it outputs quad bayer DNG files at ~90mb in size.
Running dng_validate on them does not however reveal them to be a quad bayer sensor:
CFARepeatPatternDim: Rows = 2, Cols = 2
CFAPattern:
Red Green
Green Blue
CFAPlaneColor: Red Green Blue
CFALayout: Rectangular (or square) layout
I have also checked other quad bayer sensor cameras capable of saving to DNG and they also report a "normal" bayer 2x2 pattern. So I'm trying to determine if the DNG spec actually has a way of specifying a quad bayer pattern.
If it does, great - but then why are all these quad bayer cameras not doing that?
Copy link to clipboard
Copied
There is a also the possibility that the sensor/camera internally converts ('remosaics') the quad to the regular 2x2 Bayer pattern before saving to a DNG file which can then be consumed by many existing raw processing SW that doesn't understand anything else but 2x2 Bayer (or X-Trans) as of today. The DNG spec itself of course allows for storing other patterns via the CFARepeatPatternDim tag in theory.