TWO-LINE MAC HIGH DEFINITION TELEVISION TRANSMISSION SYSTEM

摘要

A high definition television signal with a sequential scan with the standard number of lines per frame and double the frame frequency is processed to generate a single MAC line having a duration substantially equal to that of four sequential lines of standard duration. Each MAC line has two luminance components having different compression ratios. For the remaining two lines, compressed line difference signals are transmitted, thereby allowing reconstruction of all luminance lines at the receiver. Each MAC line further has a U chrominance component and a V chrominance component, alternatively compressed 1:4 and 1:2. The remaining parts of each MAC line are taken up by data signals and audio as well as the necessary clamping. The luminance and chrominance signals are prefiltered to prevent artifacts. The filtering is geared to the visual characteristics of the human visual system, i.e. diagonal spatial frequencies are subjected to more filtering then either purely horizontal or purely vertical spatial frequencies.