Which MIME type should be used for a raw image?

Question

Raw images are produced by cameras, scanners, etc. and typically give you more post-processing flexibility than JPEG images.

If I’m serving this kind of file from my web server, which media type (a.k.a. MIME type) should I use? I’m specifically interested in the CR2 files produced by recent Canon cameras, but answers could also address Adobe’s Digital Negative (DNG) format or raw files from other manufacturers’ cameras. (I didn’t see anything relevant in this list from the IANA.)

Answer 1

According to this XML file from the (defunct?) GNOME RAW Thumbnailer project, the MIME type for raw images in general is image/x-dcraw. Listed by their file extensions, here are the other file types mentioned in that file:

• ARW: image/x-sony-arw
• CR2: image/x-canon-cr2
• CRW: image/x-canon-crw
• DCR: image/x-kodak-dcr
• DNG: image/x-adobe-dng
• ERF: image/x-epson-erf
• K25: image/x-kodak-k25
• KDC: image/x-kodak-kdc
• MRW: image/x-minolta-mrw
• NEF: image/x-nikon-nef
• ORF: image/x-olympus-orf
• PEF: image/x-pentax-pef
• RAF: image/x-fuji-raf
• RAW: image/x-panasonic-raw
• SR2: image/x-sony-sr2
• SRF: image/x-sony-srf
• X3F: image/x-sigma-x3f

Answer 2

It might be too late for the author of the question, but might be helpful for others struggling with the same problem.

For .CR2 it is image/x-dcraw.

For .DNG it is image/x-adobe-dng