Started Dec 27, 2007 | Discussions thread
Gao Gao Contributing Member • Posts: 561
A look at DNG files converted from sRAW and RAW

I complied the dng_sdk from Adobe, and was running it in debugging mode. Both sRAW and RAW are converted using the standard Adobe DNG converter 4.3.1, and keeping raw data raw.

The observation is that at Stage 3 (interpolation), DNG(Raw) provides valid CFA mosaic infomation, including CFA size, pattern order etc - while DNG(sRaw) does not provide this information and the Stage 2 image is directly copied to Stage 3's output. This means the DNG converter is doing whatever interpolation needed and the DNGs it spit out are not of any CFA pattern. This perhaps explains the file size of the uncompressed DNG (slightly larger than 1936*1288*3*16/8 bytes, meaning full rgb sampling); also the DNG converter itself has become much fatter than before if I'm not wrong - meaning some extra code specially written (or ported) for sRAW might have been added to handle the interpolation at conversion time.

So my attempt to crack sRAW through DNG has pretty much hit a dead end.


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