The European Broadcasting Union (EBU) has released a position paper on High Definition Television in Europe recommending that any HD Format that is agreed should be “progressive??? scanned. As a result they will be suggesting 720p50 with the option of 1080p50 when technology permits (in relation to bandwidth limitations).

The reason for choosing 720p50 is two fold - firstly its bandwidth requirements look as though they are achievable and secondly, in perceptive tests it was felt that the average European viewer from the average viewing distance would be unlikely to see any advantage of 1080p over 720p on their likely display size (between 30-40 inches at 8ft).

The reason for picking a progressive transmission method is that in today’s environment the production process is tending towards progressive (film is progressive, as are many HD production technologies) and the display process is similarly becoming progressive (plasma and LCD devices). In such an environment the obvious place to put any “interlaced??? to “progressive??? conversion is with the broadcasters, where expensive equipment can do an excellent job; rather than in the display which generally does a pretty poor job. Equally, conversion from progressive to interlaced for an interlaced display is a relatively easy process that does not loose information.

Taking these things into consideration the EBU seems to be recommending 720p50 for broadcasters but is leaving the door open to potential 1080p50 in the future (though they have no control of broadcasters or equipment manufacturers as to if they will provide STBs with this future functionality in built).

This is of course an interesting position as the only current European HD broadcaster does so in 1080i50: an interlaced format that the EBU does not want to include in the standard.

With Sky’s HD offering coming in early 2006 - their decision on what format they will support is probably being made in the next month or so - this EBU technical paper could push them towards 720p as a broadcast standard.

The full paper can be read from the EBU Technical Review Web Site and the article can be directly downloaded as a PDF file from: High Definition for Europe - a progressive approach (PDF). Another earlier article on a related subject can be downloaded at Image Formats for HD (PDF).