JEITA  CP-3451 - 1 - Standard of Japan Electronics and Information Technology Industries Association Exchangeable image file format for digital still cameras: Exif Version 2.2 1     Scope This  standard  specifies  the  formats  to  be  used  for  images,  sound  and  tags  in  digital  still  cameras  and  in  other systems handling the image and sound files recorded by digital still cameras. NOTE−Reference documents that are indispensable for this standard are listed as Normative References in this document. 2     Definition of Terms (1) Primary image The main image data (2) Thumbnail A small image used to index the primary image. (3) Compressed data Data referred to in the JPEG standard as "entropy coded data." (4) Exif An abbreviation of Exchangeable image file format, used here as the general term for this standard and earlier versions of this standard. (5) writer A digital still camera (DSC) or other device or application software that can output an Exif file. (6) reader A device, such as a printer with memory card slot, capable of directly reading an Exif file and printing or performing other output processing, as well as application software that uses Exif tags to perform image processing for output. (7) tag A field recording ancillary data about an image. (8) tag information A description of the tag contents. 3    General 3.1 Format Structure This standard consists of the Exif image file specification and the Exif audio file specification (see Figure 1). The recording medium specification shall conform to the standard for the particular medium used and is not specified here. Recommendations on implementation are given in Annex D for directory and file naming. Exif image file specification   Exif audio file specification   Recording medium specification   Figure 1 Format structure