Research has been undertaken into higher than HD picture resolutions and frame rates for several years, with particular interest in two specific levels of spatial resolution: 3840×2160 pixels/frame and 7680×4320 pixels/frame, both of which are integer multiples of the 1920×1080 picture size of HD. The term Ultra-High Definition TV (UHDTV) however refers to much more than an increased number of pixels. Some of the features been bundled up in UHDTV in order to produce better pixels include higher frame rates, higher dynamic range, wider colour gamut, etc.
Some of these characteristics of UHDTV are specified in the ITU-R Recommendation BT.2020-2 covering both UHD picture sizes noted above. Below table shows a brief comparison of the UHDTV and HDTV (ITU-R BT.709) specifications.
| Parameter | UHDTV (ITU-R Rec. 2020) |
HDTV (ITU-R Rec. 709) |
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| Pixel count (horizontal × vertical) |
7680 × 4320 3840 × 2160 |
1920 × 1080 | |||
| Picture aspect ratio | 16: 9 | 16: 9 | |||
| Standard viewing angle (horizontal) | 100° | 30° | |||
| Frame frequency (Hz) | 120, 120/1.001, 100, 60, 60/1.001, 50, 30, 30/1.001, 25, 24, 24/1.001 | 60, 60/1.001, 50, 30, 30/1.001, 25, 24, 24/1.001 | |||
| Scan mode | Progressive | Interlaced, Progressive | |||
| Primary colours: chromaticity coordinates (CIE, 1931) |
x | y | x | y | |
| R | 0.708 | 0.292 | 0.640 | 0.330 | |
| G | 0.170 | 0.797 | 0.300 | 0.600 | |
| B | 0.131 | 0.046 | 0.150 | 0.060 | |
| Pixel aspect ratio | 1:1 (square pixels) |
1:1 (square pixels) |
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