Yes, FastRawViewer uses LibRaw (+RawSpeed +Adobe DNG SDK) to decode raw data and its own (post)processing code (written in SSE3/AVX2 assembly for speed, that's why FRV is Fast)
RawDigger uses LibRaw (+libs listed above) for decoding and dcraw_process() (with bilinear 'demosaic', fast but far from perfect), because RGB rendering is only for user reference (we plan to change demosaic to own code in future releases to provide better rendering, because many users use RawDigger as raw processor :).
I'm not familiar with Apple Core Image. It is very likely it will accept (cropped?) imgdata.rawdata.rawimage[] as input to CIRawFilter (this is flat array of unprocessed raw values decoded from camera).
Yes, FastRawViewer uses LibRaw (+RawSpeed +Adobe DNG SDK) to decode raw data and its own (post)processing code (written in SSE3/AVX2 assembly for speed, that's why FRV is Fast)
RawDigger uses LibRaw (+libs listed above) for decoding and dcraw_process() (with bilinear 'demosaic', fast but far from perfect), because RGB rendering is only for user reference (we plan to change demosaic to own code in future releases to provide better rendering, because many users use RawDigger as raw processor :).
I'm not familiar with Apple Core Image. It is very likely it will accept (cropped?) imgdata.rawdata.rawimage[] as input to CIRawFilter (this is flat array of unprocessed raw values decoded from camera).