The ITU has defined common image formats. A standard definition image of 352 x 240 pixels is described for computers. For HDTV production the HD-CIF preferred format is defined in ITU-R BT.709-4 as 1920 x 1080 pixels, 16:9 aspect ratio with progressive frame rates of 24, 25 and 30 Hz (including segmented scan) and interlace field rates of 50 and 60 Hz. This has helped to secure the 1920 x 1080 format as the basis for international program exchange.
See also: ITU-R BT.709