Originally Posted by Woof Woof
You can resize an image or you can resample an image. Both won't get you a true hd image but with good resampling algorithms, it can come close. Particularly with animated media.
My old Toshiba XA2 with the Reon chipset did an amazing job upscaling Incredibles.
As stated, the scaler can only work with what's there in the final video master. Video that is sent as SD or less than HD resolution will be missing some of the finer details that are present, because they were mastered in a lower resolution.
A good analogy to this would be using SNES Super Mario (in his big form) and say a Wii's Super Mario. And for the sake of argument we're going to remain in the 2D realm, using a side shot view for the Wii Mario.
The SNES Super Mario is relatively small, and is made up of only a scant number of pixels, while the Wii Super Mario is rather large, and is made up of tens of thousands of pixels. Sure, you could blow up the SNES Mario to the same size as the Wii mario, but you will get one of the following as the result:
1) Using simple scaling, you get a big SNES Mario, but you can see him as made up of hundreds of blocks, and man does he ever look jagged around the edges...and the arms...and eyes...and nose...and...well, you get the picture.
2) Using interpolation (a form of anti-aliasing), you can smooth out the edges because the interpolator adds in pixels between the jagged areas to create smoother images. The problem is that you still only have the detail of the original model to go off of, and it's a fairly blurry end result. Big, but it looks like it's been through Filter Hell.
As for "enhancing HD material", um...yeah. Anybody that believes it can enhance 1080p, I've got a bridge I'd like to sell you. As stated above, 1:1 pixel ratio video already has
everything there is to have in it. The only thing that the TV's processor can do beyond frame interpolation (Samsung's AutoMotionPlus 120/240 Hz picture "smoothing" modes) is add noise to the image. And we ALL know how much we just love
So you can get a small, but clear image, or a larger but somewhat blurry image from a scaler. But you aren't going to get extra detail that isn't there in the first place.