テレビやパソコンディスプレイの4Kや8Kって?

Kは1,000の単位。「1,000m = 1km」や「1,000g = 1kg」などと同じ。
ディスプレイでいう4K(=4,000)は「画像解像度の幅(ピクセル数)」
具体的には「3840×2160」の規格を指すことが多い(4000に満たないが)。

正式な国際標準規格は「Ultra HD(UHD)」

ITU-R BT.2100-1

Parameter Values
Image Container  1a Shape 16:9
Container Pixel count  1b

Horizontal × Vertical

7 680 × 4 320

3 840 × 2 160

1 920 × 1 080

Sampling lattice Orthogonal
Pixel aspect ratio 1:1 (square pixels)
Pixel addressing Pixel ordering in each row is from left to right, and rows
are ordered from top to bottom.
Frame frequency (Hz) 120, 120/1.001,100, 60, 60/1.001, 50, 30, 30/1.001, 25, 24, 24/1.001
Image Format Progressive
NOTE 1a – Container is used to define the horizontal and vertical constraints of the image format.

NOTE 1b – Productions should use the highest resolution image format that is practical. It is recognized that in many cases high resolution productions will be down-sampled to lower resolution formats for distribution. It is known that producing in a higher resolution format, and then electronically down-sampling for distribution, yields superior quality than producing at the resolution used for distribution.

出典:国際電気通信連合(ITU)

投稿者: iisys