Photoshop color mode and application (on)

1 Photoshop color mode

Photoshop color modes include Bitmap, GrauScale, RGB, CMYK, CIE Lab, HSB, Index Color, Indexed Color, Duotone, and Multichannel î—¤ Multichannle. We need to choose different color modes according to different needs, so that we can maximize the trueness of color and use color to better express the ideas and intentions we need to express.

1) RGB mode

The RGB mode is based on the principle of the mixing of the three primary colors in the natural world, and the color produced is the color of the additive color space. Use R, G, B as primary colors to represent thousands of colors. If the color depth is 8 bits, the range of R, G, B colors is 0-255, that is, 28 = 256. The total number of colors in the RGB color space is 28 x 3 = 224, which is 16 700 000 colors.

2) CMYK mode

The CMYK mode is a printing or printing mode, and the method of generating colors is called color subtracting. When the same color is expressed by different color materials, the dot sizes of C, M, Y, and K are different, that is, if different brands of ink express the same color, the C, M, Y, and K values ​​are different.

3) CIE Lab mode

The Lab color represents the color with one luminance component L and two color components a and b. Where L represents the brightness, the value range is 0-100. The a component represents the spectral change from green to red. A is positive, indicating that the color is red, a is negative, indicating that the color is green. The b component represents the spectral change from blue to yellow, b being positive indicating that the color is yellow, and b being negative indicating that the color is blue. A and b can range from +128 to -128. In the Photoshop Color palette, a and b can range from +120 to -120.

4) Other color modes

(1) HSB mode

This is a color mode based on the human eye. It is a color appearance method that describes colors using the three color attributes of Hue (H), Saturation (S), and Brightness (B).

Note that B is not an absolute value of luminance but a relative value, ie, relative luminance, expressed as a percentage. The brightness varies from 0% to 100%: 0% represents black; 100% represents white.

î—¤ (2) Bitmap mode

Black and white color mode. The use of binary values ​​that are black or white represents the color. This mode has only one bit of color depth in the computer and is mainly used to represent black and white text and line drawings.

î—¤ (3) GrauScale mode

Grayscale mode. The white-gray-black gradation change is represented by using 256 levels of grayscale. The color of each pixel has a 0-255 level change, 0 represents black, 255 represents white, and can also be represented by a dot change of 0% to 100%. Only light and dark changes in grayscale mode.

î—¤ (4)Indexed Color mode

The index color mode. This is an image pattern commonly used on the web and in animation. When a color image is converted to an index color image, it contains nearly 256 colors.

By limiting the color palette, the index color can reduce the file size while maintaining the visual quality of the image. However, only limited editing is possible in this mode. For further editing, temporarily convert to RGB mode.

î—¤ (5) Duotones mode

That is dual tone mode. The two-tone mode uses two to four color inks to create two-tone (two colors), three-tone (three colors), and four-tone (four colors) color-graded images. In the process of converting a grayscale image to a dual tone mode, the tone can be edited to produce a special effect. The most important use of the dual tone mode is to use as little color as possible to represent as many color levels as possible, which has an effect on reducing printing costs.

î—¤ (6) Multi-channel mode

Each channel of this mode uses 256 gray levels. Multichannel images are useful for special printing.

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