I was wondering if the resolution matters when downscaling. Basically - if I convert 1080p to 480p and 720p to 480p, would the results look the same since they are being downscaled to the same resolution even though they are different resolutions before?
1 Answer
This depends on the scaling algorythm - they would look extremely similar, but probably not bit-for-bit identical.
Some simple math can prove the point. 1080 / 480 = 2.25, while 720 / 480.0 = 1.5 - Thus if the downscaling algorithm takes pixels and averages them out it will get slightly different answers. Likewise, if it just takes one of the pixels it will sometimes pick a different one.