ultra high definition (UHD)
Ultra High Definition (UHD) is a quality rating for extremely high- resolution imaging, Extremely High-Resolution Imageries( EHRI). The high-resolution Ultra HD has a resolution of 7,680 x 4,320 pixels and is designated as 8K or UHD-2. In addition, there is a lower-resolution variant of 3,840 x 2,160 pixels for UHDTV, designated 4K or UHD-1, and another variant of 4,096 × 2,160 pixels, designated 4k (small k), used in D-Cinema.
Both variants have a 16:9 aspect ratio, and the resolution of the 8K variant is 16 times that of high definition (HD). The 4K variant brings it to four times the resolution. The pixel count is 33.2 megapixels( MP) in the 8K standard, and 8.3 megapixels in the 4K standard.
Frame rates for 8K can be 24, 25, 30, 50, 60, 100, or 120 frames per second. The color space for UHD-1 is specified in BT.709, that of UHD-2 in BT.2020. The latter works with resolutions of 10 bits or 12 bits per pixel and has a high dynamic range, High Dynamic Range( HDR). The corresponding method used in HDR displays and HDR TVs is called HDR10, referring to the 10-bit resolution.
In UHD-1, it is 8 or 10 bits per pixel. And the color subsampling is 4:2:0, 4:2:2 and 4:4:4. This results in net data rates of between 3 Gbit/s and 36 Gbit/s for UHD video. As for frame rates, resolution and color subsampling, these differ from those of the 4K standard in UHD-2. The resolution is higher according to the larger color space and the frame rate knows 100 Hz and 120 Hz. The data rates are therefore about four times higher.
The term Ultra High Definition is used for the resolution of all components of a UHD system or Ultra- HDTV (UHDTV): for digital cameras, recorders, displays and projectors.
In terms of transmission technology, Ultra HD can be transmitted with 10 Gigabit Ethernet, in the mobile sector and in automotive technology with APIX 3 or with a lower refresh rate of 30 Hz with Mobile High-Definition Link( MHL).