Except with scaling down, yes, you lose pixels, but none are added. Nvidia cards actually use this to make games look better with DSR (Dynamic Super Resolution) - the video card renders the image at 4K and reduces it to 1080p, resulting in a better looking image. Even professional photographers do this with images they'll display on the web, as it reduces noise.Imperf3kt wrote:Scaling images down is actually more detrimental to image quality than scaling it up.JayBlue wrote: I see, so the common verdict is to go with 1920x1080 so it can fit HD screens and people can shrink the size down to fit all other sizes.
If you have an image with a 3 pixels wide line drawn on it and you scale it from 1080p to 720p, you'll end up with a 1.33 pixels wide line. What happened to the other 1.7666^ pixels? You lose them, they're gone forever.
But if you scale that image up, you end up with a 6.75 pixel wide line.
taking into account the percentage of change, you have 1.875 pixels per edge that will be blurred. But as long as you properly aliased the image before it was scaled up, there should be no real issue.
The trick is to do the scaling down in an application like Photoshop, using the proper settings. I don't just plug 4K images into a game engine for it to resize on it's own.
With scaling up, the computer is making up pixels (interpolating) to plug into holes on a 'best guess' basis. This results in a 'fuzzy' or 'blurry' image. It can also introduce noise into the image. Maybe some people can deal with this, but as an artist, and someone who has worked in film, I can't stand it. It's like trying to watch a movie on VHS after watching the Blu-Ray. It's going to diminish my enjoyment considerably.
And if you are making the art, why NOT make it a higher resolution? It doesn't take that much more effort to make a background or sprite at a higher resolution versus a smaller one. And if you are thinking of ever printing your art or using it for marketing materials, you'll need it a higher resolution anyway. Instead of having to create brand new images, you can just go back to your original raw file and it's all there.
Not to mention, this is how comic book art has been created for DECADES. The art is drawn and inked on 11x17 or larger Bristol boards and then reduced to 6.5 x 10.25 for print. It hides mistakes, and improves the look of the lines. Even comic artists working digitally now still do this, for the same reasons.