File formats define the syntax, that is to say the inner structure, of data. Depending on the intended applications, there are various available file formats for photos. While some formats are mostly used for exchanging photos, other formats are optimised for further editing. Thanks to Exif data, additional information can also be added to the files.
JPEG is an acronym for “Joint Photographic Experts Group” and labels the most popular file format for pictures. Thanks to its methods of compression and coding, JPEG files are capable of storing high-quality photos even with a limited amount of storage space. JPEG covers a colour space of 16.7 million colours and is supported by almost all popular applications and cameras. The JPEG format is especially well suited for pictures with flowing and smooth transitions.
The “Tagged Image File Format” (TIFF) was originally developed for saving scanned raster graphics. In addition to PDF and EPS, it’s a common file format for the exchange of data in prepress. Contrary to the JPEG format, TIFF supports CMYK profiles, which are used in printing. Thanks to its high colour depth, TIFF files are often used for the loss-free exchange of pictures. Due to their very high quality, pictures that are saved as a TIFF file are considerably larger in size.
The raw data from a camera is labelled as a RAW file. Different file-endings are used depending on the manufacturer. Even though almost every camera is capable of providing raw data, a universal standard has yet to be established. The benefit of saving pictures as RAW files is that there is no loss of quality or colour space. Special software makes it possible to edit the photos later. This makes it possible to make corrections in the areas of definition, tonal values, saturation, and white balance. Since RAW files are not compressed, the file sizes tend to be considerably large.
The “Exchangeable Image File Format” (Exif) is a standard format for saving metadata with digital photos. These data are displayed in the header of the photo’s file and can contain information about the picture itself as well as the hardware used. Typical Exif entries are the date and time the picture was taken, orientation, focal length, exposure time, and ISO-value. Professionals often also add information about the creator of the photo as well as copyright. Compressed JPEG files as well as non-compressed TIFF and RAW photos support Exif data.