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Brief introduction
Image color mode refers to different combinations of colors in a computer. Different color modes have different characteristics and can be exchanged with each other. Color mode is the most basic knowledge of graphic design. Here are the image color modes included in Photoshop.
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1. RGB mode
RGB is the color mode of colored light. R stands for Red, G stands for Green and B stands for Blue. In RGB mode, other colors can be produced by the superposition of red, green and blue, so this mode is also called additive mode. Many devices, such as displays, projection devices and televisions, depend on this additive color mode.
2. CMYK mode
CMYK mode is a color mode in which four basic colors, Cyan, Megenta, Yellow and black, are combined into different colors. This is a subtractive color mode. This subtractive color mode is applied in printing and printing.
3, Lab mode
Lab mode consists of three channels, one of which is brightness, that is, L. The other two are color channels, represented by a and b. Channel A includes colors ranging from dark green (bottom brightness value) to gray (middle brightness value) and then to bright pink (high brightness value); Channel B is from bright blue (bottom brightness value) to gray (middle brightness value) and then to yellow (high brightness value). In Lab mode, the colors will be mixed to produce bright colors. This model was published by CIE in 1976.
4. HSB mode
In HSB mode, H represents hue, S represents saturation and B represents brightness. Hue: it is a solid color, that is, a single color that constitutes the visible spectrum. Saturation: Also called chroma. Indicates the purity of color, which is gray when it is . White, black and other gray colors have no saturation. Brightness: It is the brightness of color. It is black when it is .
5. Indexed mode
Indexed mode is indexed color mode, also called mapping color. In this mode, only one file with 8bit color depth can be stored, that is, up to 256 colors. And the colors are all predefined. This color mode is not very effective in filter processing, but because of its small file storage space, it is mostly used in multimedia production and the Internet.
6. GrayScale mode
There are only grayscales in the grayscale mode, which includes 256 shades of gray from black to white. In the grayscale file, the color saturation of the image is , and brightness is the only option that can affect the grayscale image. When a color file is converted into a grayscale file, all color information will be removed from the file. Photoshop allows a grayscale file to be converted into a color mode file, but it cannot restore the original color unchanged.
7. Bitmap mode
The black-and-white bitmap mode is an image composed of only black and white pixels. It should be noted that only gray-scale images or multi-channel images can be converted into Bitmap mode. After the image is converted into Bitmap mode, other editing cannot be performed, and even the image in gray-scale mode cannot be restored.
8. Duotone two-color overprint mode
Duotone mode uses a gray ink or color ink to render a gray image, which is a two-color overprint mode or a same-color shading overprint mode.