Upon applications of digital technology to TV, the difference between TV and multimedia slowly disappears by the improvement and manipulation of pictures. It is a new media unimagined before by the improvement of the current TV and by the maximization of the visual psychology due to the detailed output.
Horizontal resolution is determined by signal range of luminance of the picture.
Compared to 4.2Mhz of NTSC , HDTV has 22 MHz, about five times high resolution, but horizontal resolution is about twice better, and has 1000 lines. The main difference between HDTV and NTSC is in that in the HDTV method there is no frequency multiplexing, but the Cross Color and cross luminance can be completely eliminated by sending the multiplexing of time sharing. HDTV assumes the view to be three time higher in screen height and has a power and real situation right on the screen. A wide range of applications is being tested in the fields such as movie, printing, publishing, medical applications and education. Some of them is being used.