CCIR 601, Future File Image or the Last Universal Video Standard?

The fundamental nature of television standards has changed little in the first 60 years of broadcasting. The elegant solutions designed in the research laboratories of the twenties and thirties still endure to this day providing hundreds of millions of viewers with good images on economical home screens and programme makers with economical solutions to acquisition an production. Whilst two of the original 405,525, 625, and 819 line scanning standards have since fallen by the wayside, 525 and 625 are still going strong and are set to be with us for at least the next twenty years (so hopes the author and many millions of others who have recently bought new home receivers !). The ingenious aspect of those early standards was to incorporate a form of image compression which traded off spatial resolution for temporal resolution on moving scenes. This trick of using 2:1 interlace for the line scan / field scan relationship made the home receiver and studio camera not only technologically possible but also economised on channel bandwidth and in one step eliminated large area flicker and doubled the temporal resolution compared to the 24 frames per second of the cinema.

Published

1996-10

Content type

Original Research

DOI

10.5594/M00118

ISBN

978-1-61482-925-6