An explanation of resolutions on PS3

[edepot]

The PS3 normally outputs a predefined set of resolutions to the HDTV.

1920x1080p
1920x1080i
1280x720p
720x480p
720x480i

The HDTV LCD screen has a predetermined number of pixels (horizontal and vertical pixels lines), and you would set your PS3 display to match
the exact horizontal and vertical pixel lines of your LCD HDTV. However, you can set your PS3 to a lower resolution and let the TV automatically
stretch the screen to fill it's native higher resolution display. For example, the PS3 can output 1280x720p to the 1920x1080p display, and
the display will use hardware to stretch the image to 1920x1080 pixels. When this happens some pixels are wider or taller.

A game is determined to be outputting 1080p if the HDTV display detects the signal from the PS3 to be 1920x1080, and no hardware stretching
by the display is done. HOWEVER, a game outputting 1080p does not mean the picture contains 1920x1080 possible different pixels. Sometimes
the game developers cheat by actually having the picture rendered at 1600x1080 or 1280x1080 but use software to stretch the
image in the buffer to 1920x1080 before outputting to the hdtv.

The example games below all output 1920x1080 to the HDTV display, but as you can see, the images are rendered at a lower resolution than 1920x1080
and then stretched via software, leaving duplicate repeat pixels on slanted lines. Note that although the software stretching happens after rendering the
image, sometimes texture rendering can be done separately at the native high resolution of the hdtv display. In this case for GranTurismoHD and
GranTurismoPrologue, the textures of the banners and flags are not confined into the same lower rendering resolution (and software stretched) of the background. The result is that the textures can match the native 1920x1080 resolution of the display. Games like StarDustHD seems to show
similar behavior... the objects are of a lower resolution than the object descriptions, which indicates that the object descriptions (words) are
most likely not software stretched, or at least stretched less.