Samsung Galaxy Note

Zach Honig, Engadget:

1280 x 800 pixels in a smartphone display is quite a feat, and it’s just as impressive to behold as it sounds. The Note’s 5.3-inch Super AMOLED screen is incredibly bright, vibrant and detailed, thanks to its 285ppi resolution.

1280×800 is unique for smartphones. I’m surprised Samsung broke away from 16:9.

What is the correct method of calculating resolution (as in ppi) for PenTile Matrix displays?

Pixels on a PenTile Matrix display are not hardwired pixels but virtual pixels: a pixel can be made up of 2×1 or 2×2 sub-pixels. And those sub-pixels can be made up of RG, BG, GR, GB or RGxBG, GRxGB, BGxRG, GBxGR.

Is 285 ppi accurate for the 5.3-inch RGBG Super AMOLED display? In light of virtual pixels is there a better method of measuring resolution?