A) Extended (or Enhanced) Definition Television is a proposed intermediate television system for evolution to full HDTV that offers picture quality substantially improved over conventional 525-line or 625-line receivers, by employing techniques at the transmitter and at the receiver that are transparent to (and cause no visible quality degradation to) existing 525-line or 625-line receivers. One example of EDTV is the improved separation of luminance and colour components by pre-combing the signals prior to transmission.

Also see Improved Definition Television. b) Specifically, a video format with sampling frequencies 18 MHz (Y), 4.5 MHz (C), and resolution 960 pixels by 576 lines (Y), 480 pixels by 288 lines (C).