Does Upscaling increase the quality of the image, or just the size?

[1-800-Get-Rags]

I heard this from somebody and I wanted to see what was up.

I thought it stretched the image to make the image fit a larger screen. Maybe I just don't know what's up? Can somebody clarify?

 

[audie-tron25]

Upscaling stretches the image to fit the resolution you're displaying at. For example, a 720p being upscaled to fit a 1080p screen. This is the opposite of downscaling which renders an image at a higher resolution before downscaling to your resolution. Downscaling makes gives the image a higher quality.

 

[thor220]

If upscaling did increase image quality the consoles would last much longer. Upscaling is a simple process in which a algorithm (sometimes stored in software, sometimes in the hardware like in many Blu-ray players) interpolates (that is, guesses the contents of the extra pixels). Since it doesn't actually have the data the best it can do is guess. This process cannot add detail to an image but it can make it appear sharper / more defined, which is why some people say it improves the image quality. This mostly applies to TVs though, as detail is often lost due to the large size of the pixels. Have you ran a computer through your TV and noticed that you have to lower your resolution so that text is readable? Same effect applies to other media.