Originally Posted by Latinoheat
There are many different video signals in use which are not the same resolution (neither are all of the displays), thus some form of resolution adaptation (video scaling) is required to properly frame a video signal to a display device meaning it's scales it to fit the screen but does not up convert the signal to 1080p other wise a 1080i or 720p signal would get up converted to 1080p and you would see a difference.
If what you mean is that the TV can't make up for missing data in source material that isn't 1080i or 1080p then that's correct. I had a problem understanding what you wrote.
In the case of 1080i, the deinterlacing process done in the TV or other device should be identical to a 1080p transmission of the same data because all the data is there..
In the case of 720p (needs scaling) and 480i (needs deinterlacing and scaling), they must be converted to 1080p before they can be displayed. The image quality will be effected because there is less data to work with and the video processing needed does a lot of guessing. Therefore 480i converted to 1080p will never be mistaken for true 1080p, but some high quality SD DVDs come a lot closer than any broadcast SDTV because there is more data on a DVD.Edited by htwaits - 3/15/13 at 1:08am