What is Ultra HD Premium?


 

Color Depth (Color Depth) is another concept closely related to the display screen and color besides YCbCr (color sampling rate).

Color depth , which is a unit that expresses the number of colors in digital images by bit number. Bit is a binary unit calculated by computer, the most basic data or message that can be processed in a computer.
The color depth is expressed by exponentiation. The higher the bit number, the higher the color depth value, the more colors the image can express, and the smoother the transition between colors.

A 4K/Ultra TV must be able to receive and process a 10-bit colour signal, which refers to the number of colours a video signal contains. Blu-rays use 8-bit colour, which equates to just over 16 million individual colours.

10-bit colour, often called ‘deep colour’, contains over a billion colours. This doesn’t mean the TV has to be able to display all those colours, only that it can process the signal. Most decent ones can, so there’s no problem here.

In practical applications, the UHD Alliance (UHD Alliance) announced the "Ultra HD Premium" certification standard at the 2016 CES show, the color depth must support at least 10 bit! And 10 bit is also the color depth adopted by the current mainstream HDR image format (Dolby Vision color character depth can reach 12 bit).

Whether it is 10 bits or 12 bits, this number is more like a brightness level, because the higher the number, the more careful, smoother and more layered the brightness changes provided. And these changes are not only in the black and white picture, all the colors appearing in the image will be changed due to this color depth. The color depth is not something produced by the playback device or the decoding process. It is reflected in the color depth capture capability of the shooting device. In other words, a device with a 12-bit shooting capability can shoot videos with the corresponding color depth. , Through post-production and compression processing, stored in a Blu-ray disc or hard disk, and then replayed through a system (cable, player, display device) with 12 bit transmission capability.