There is a method of resizing images/videos without significant distortions known as seam carving. Any image proportions you want–this is really awesome!
Watch this presentation discussing implementation for videos: http://www.youtube.com/watch?v=AJtE8afwJEg
I think this would lead to weird issues with game behavior whereby it would look nice and undistorted, but something like a bullet tracking across the screen would be all herky-jerky as the various slices were carved out (or not). Dunno, though. I am a big fan of the seam carving plugin for GIMP with static images, for sure.
I don’t know either. 
But this presentation of seam carving for videos looks promising. I thought it would be nice to have such thing in an emulator.
It seems that even Google is interested in applying this technology for videos: http://googleresearch.blogspot.com/2010 … video.html
You can see a video of their technique here: http://www.youtube.com/watch?feature=pl … qMovlLlr_0
The main issues I see for use in emulation are: 1.) it requires analysis and comparison of previous and current frames, which necessarily introduces “lag” and 2.) distortions are still happening, but they’re not happening uniformly, which is good for subjective measures of quality but not for game logic.
Here’s an example of #2: let’s imagine you’re playing Super Mario Bros and there’s a big pit you have to jump over. The algo sees an area with nothing important (i.e., just blank sky, not even any ground) and starts carving it out as you approach it (meanwhile, it’s preserving the goombas you’re jumping on, etc., so they all look nice). This makes the pit seem pretty small, so you don’t bother building up speed because a walking jump can cover it. Then, when you go to jump over it, it stops carving out those segments because they are now considered important (the main character is over/in them and they’re the focus of motion), and it seems like your jump slows down and/or the pit expands, causing you to fall into it.
Thus, even though simple squishing/stretching of the AR looks subjectively bad, it makes more sense in this case because it’s consistent, which preserves the game logic.
You’re probably right. But maybe it would be good to do tests with static images from games first to see what we can get.
Not to mention that most games are tilebased, the logic would have to consider that and… I don’t know repeat tile regions or something… I don’t think this works for stretching AR it’s better suited to shrink image sizes imho.
what might be more feasible in the short run is to do what some TVs do when stretching 4:3 content to 16:9, keeping the center square relatively distortion free but stretching the sides slightly so you notice it less being that your eye is concentrated in the center of the screen?
In the current state of seam carving it wouldn’t look good at all. It only works well in very special cases. Its not that new either, its been in photoshop since cs4. I tried it once for a FF7 restoration project I was working on when I was younger and it looks rediculous. Not even close to acceptable.