I am looking for some free tools that will let me easily process the pixel data in a RAW file (DNG or NEF) while keeping the metadata untouched. Are there any such tools?
Use case: I am experimenting with reducing banding noise. I can get the un-demosaiced data from the RAW file using dcraw and write it into a 16-bit TIFF:
dcraw -o 0 -D -T -4. I can then process this data using various tools (e.g. Mathematica/MATLAB) and try to reduce the noise. Now how can I put the processed data back into a raw file (I'm thinking DNG) and keep all the original metadata (camera, settings, lens) so I can feed it to a raw processor such as ACR and make use of automatic lens corrections and camera profiles?