On Picture Quality in Television Systems

Improving picture quality can be achieved with respect to VLSI techniques by signal processing within the given television standards, extending them or by complete new HDTV standards. In this paper some methods of improving picture quality published earlier are investigated. Subjective picture quality has been determined by subjective assessments. — A quality comparison is described between — standard television system, — (—)progressive scan reproduction, — vertical pre- and postfiltering, — diagonal pre- and postfiltering, — high line number (HDTV-) system — The result of this comparison is, that the picture quality with diagonal pre- and postfiltering is superior to all other compatible improvements. Compared with the standard television system an improvement of at least 2 grades of the CCIR comparison scale is achievable. The real HDTV system is about 2.5 grades better than the standard system — at the price of a fourfold bandwidth for the transmission channel. — As a further result, it can be seen by these tests, that by progressive scan reproduction also a good improvement of picture quality can be achieved. The achieved subjective impression of resolution and sharpness is comparable to that of the vertical pre- and postfiltering method — therefore, there is no longer a justification for a general reduction of vertical resolution by Kell's factor.

Print ISSN

0036-1682

Published

1984-01

Content type

Original Research

DOI

10.5594/J16819