[cascade]

I have a Sharp LC-37GA6E HD Ready Lcd tv when i try to output a 1080i signal to it from my Xbox 360 the picture is blurred it looks fine in 720p the resolution of the display is 1366 x 768. i'm not to clever with the details but is it because the tv is trying to upscale to 1080i. i put this in the 360 forum but thought i would get a much more grown up answer here, only joking

[DarkEntity]

Your TV from what i understand will be upscaling an interlaced picture hence not as nice as the 720p pan and scan image.

[redpavlos]

LCDs are display devices that inherently use progressive display addressing.

So your display will be scan-converting whatever is input to it to 1366x768 progressive.

Good scan conversion is technically much more difficult to achieve when going from interlaced to progressive, particularly when dealing with motion, compared to simply rescaling from one progressive format to another. So it really comes down to how good the scaler is in any particular display device, and they vary quite a lot.

You'll see on these forums that quite a few people are prepared to pay £1,000 upwards for an external scaler that does a better job than the less complex scalers used in most displays to keep the price down.

[Welwynnick]

The most importantvideo processing stage is generally de-interlacing - that is interlaced to progressive converson. This is difficult and expensive and often looks bad. It is best performed at the lowest resolution possible - 576i or whatever is least processed. 1080i has usually been de-interlaced, upscaled and then, perversely, interlaced!

Trying to de-interlace 1080i well is like pushing water uphill.

All those previous processes, each one badly executed and degrading the picture at every stage, and then you leave the inept displays to do the worst thing possible with the most difficult format of all. It is doomed to fuzzy failure!

720p probably makes the most sense for 720 and 768 line flat panels.
1080i is probably a relic of US CRT HDTVs that could display 1080i beautifully.

Nick

[cascade]

Thansk for all your replies, great help