ITU-R Recommendation 709, usually abbreviated Rec. 709, BT.709, or ITU-R 709, is a standard developed by the Radiocommunication Sector of the International Telecommunication Union (ITU-R) for image encoding and signal characteristics of high-definition television (HDTV). The standard specifies a scheme for digital encoding of colors as triplets of small integers, a widescreen format with 1080 active lines per picture and 1920 square pixels per line, as well as several details of signal capture, transmission, and display. While directed to HDTV, some of its specifications have also been adopted for other uses. Rec. 709 is also used for HD tier Blu-ray.