Grayscale, also known as color scale or grayscale, refers to the degree of light and dark changes in pixel luminescence. A base color grayscale generally has 8 levels to 1024 levels. For example, if the grayscale of each primary color is 256 levels, for dual color screens, the display color is 256×256 = 64K colors, also known as the screen for the 256-color display. For digital display technology, grayscale is the determining factor for the number of colors displayed.

Generally speaking, the higher the grayscale, the richer the colors displayed, the more detailed the picture is, and the easier it is to show the rich details.

Gray level mainly depends on the system’s A/D conversion bits, of course, the system’s video processing chip, memory, and transmission system provide the corresponding bit support to do. At present, the domestic LED display mainly uses an 8-bit processing system, that is, 256 (28) levels of gray. The simple understanding is from black to white a total of 256 kinds of brightness changes. In the use of RGB three primary colors can constitute 256x256x256 = 16777216 kinds of colors. That is, the commonly said 16 trillion colors. International brand display mainly adopts a 10-bit processing system, that is, 1024 levels of gray, RGB three primary colors can constitute 1.07 billion kinds of colors.

256 grayscale level

Although the grayscale is the deciding factor to determine the number of colors, it is not to say that the larger the unlimited the better. Because first of all, the resolution of the human eye is limited, and then the system processing bit increase will involve the system video processing, storage, transmission, scanning and other changes in various aspects, the cost has increased sharply, but the cost performance declined. In general, civilian or commercial-grade products can be used with an 8-bit system, and broadcast-grade products can be used with a 10-bit system.

Grayscale nonlinear transformation refers to the transformation of grayscale data according to empirical data or some arithmetic nonlinear relationship before providing display to the display.

Since LEDs are linear devices, they have different non-linear display characteristics than traditional displays. In order to make the LED display effect can be in line with the traditional data source at the same time not lose a gray level, generally in the LED display system after the level will do gray data non-linear transformation, transformed data bits will increase (to ensure that no loss of gray data).

Now some domestic control system suppliers’ so-called 4096 level grayscale or 16384 level grayscale or higher refers to the grayscale level after nonlinear transformation. 4096 level is the use of the 8-bit source to 12-bit space nonlinear transformation technology, and 16384 level is the use of 8-bit to 16-bit nonlinear transformation technology. By 8-bit source to do nonlinear transformation, the converted space is definitely larger than the 8-bit source. It is usually at least 10 bits. As with grayscale, this parameter is not as large as it should be. 12 bits is generally enough to do the transformation.