Digital camera RAW file extensions

Digital camera RAW file extensions category contains various RAW image file formats taken by various digital cameras, image scanners or other suitable devices for recording pictures. These RAW files contain "raw" unprocessed data directly from the image sensor of the device. They are called "raw" because they are not ready to be printed or directly edited with common bitmap graphics editor. RAW files are edited using special photo software, which performs a variety of photo correction and photos are exported to a common bitmap formats such as .jpg and original photos in RAW format remains unchanged.
These files contain all the data needed to produce a viewable image, they are however, considerably 2-6 times larger in the file size. Most RAW files are based on TIFF standard. However, each vendor might include some non-standard meta data like header, image tags as well as encryption for some of the tagged data.

Each vendor usually uses his own file extension for its RAW format. Some of the common ones include CR2 (Canon digital cameras), NEF (Nikon), IIQ (Phase One), 3FR (Hasselblad), DCR, K25, KDC (Kodak), ERF (Epson), MEF (Mamiya), MOS (Leaf), ORF (Olympus), PEF (Pentax), RW2 (Panasonic) and ARW, SRF, SR2 (Sony).

The structure of RAW files in the the ISO standard raw image format look similar to this:
- A short file header that contains an indicator of the byte-ordering of the file, a file identifier and an offset into the main file data.
- Camera sensor metadata needed to exactly interpret the sensor image data.
- Image metadata required for inclusion in any photo database software - the exposure settings, camera/scanner/lens model, date, place of shoot, author etc.
- Some RAW file formats might also contain standardized metadata section in EXIF format.
- Image thumbnail, sometimes also small image in JPEG format used for a quick preview.
- The sensor image data.