RGB color space

RGB color space

The theory of RGB three primary colors, that is: there are three types of cone cells in the retina, each containing red, green, and blue light-sensitive visual pigments. When a certain wavelength of light acts on the retina, the three cone cells are made in a certain proportion. Respectively produce different degrees of excitement, such information is transmitted to the brain center, and a certain color sensation is produced.

After the invention of the display, from the black and white display to the color display, people began to use phosphors (CRT, plasma display) that emit different colors of light, or different colors of color filters (LCD), or different colors of semiconductor light emitting devices (OLED and LED large-scale full-color display cards) to form colors, without exception, three color luminous bodies of Red, Green and Blue are selected as the basic light-emitting units. By controlling their luminous intensity, most of the natural colors that human eyes can feel are combined.

The RGB color space is based on the three basic colors of R (Red), G (Green), and B (Blue), which are superimposed in different degrees to produce a rich and wide range of colors, so it is commonly called the three-primary color mode.

RGB space is the most commonly used color display model in daily life, and most of the CRT monitors of TV sets and computers use this model. Any color in nature can be a mixture of red, green, and blue. The colors that people see in real life are mostly mixed colors. The naked eye can recognize all colors in the world, while RGB is almost Can be combined into all the colors in the world!

RGB color range

Each element of RGB occupies 1 byte in computer memory, 1 byte is equal to 8 bits, so the value range of each element of RGB is: 0~256, then the combination of three colors 256x256x256 equals one thousand six There are one hundred and seventy-seven thousand two hundred and sixteen colors, so many colors can cover almost all the colors in the world! Therefore, ordinary TVs, computer screens, and any display instruments will be displayed through this RGB color space!

Single channel and multi channel

Single channel:

Commonly known as a grayscale image, each pixel can only have one value to represent the color, its pixel value is between 0 and 255, 0 is black, 255 is white, and the intermediate value is some different levels of gray. It can be said that the gray is The transition color between black and white!

Note that this value is not any element in RGB. The display device directly displays the pixel value in a single channel through the CRT (color cathode ray picture tube) to display a black and white image. The higher the value, the brighter the black image, and the general gray value will not be More than 125!

multi-channel:

Multi-channel is the three primary colors of RGB. Each pixel has three bytes to represent (RGB). The maximum value range is 0-255, which can be combined into millions of colors.