Dumping unmodified raw image data from raw files?

[rt966298]

@ggbutcher

Now, the data in the file should be contiguous, at least logically, and any information with regard to that offset and size can be used like is already done in reallyraw2dat.cpp. That approach requires a metadata library that can present those tags; exiv2 then becomes a potentially useful approach.

Yeah, I think exiv2 might provide a better starting point for the general case since it already dumps the raw image data when writing files, and if there’s not an analogous way to do this with libraw.

@ggbutcher

My knowledge of available hash algorithms is a bit dated, but if you’re not worried about vectors of compromise most any should work.

I think md5 should be sufficient for most people, and it would work well with the already-existing 128-bit RawDataUniqueID EXIF tag.

Support for more hashing algorithms could always be added down the road for people concerned about collisions.

Eventually, the command-line options might look something like this:

reallyraw2dat [ -v ] -i < infile > [ -o < outfile > | -stdout | -md5 | -sha256 | -sha512 | … ]