Ps 11th for beginners to elaborate on the color mode of Photoshop-ps tutorial

RGB, CMYK, LAB, HSB ...... Many friends may have seen these color patterns, but do you know about them? Most of my friends will say they don't know. Color pattern is the most basic knowledge of graphic design. how can this problem be solved? Each mode has its own advantages and disadvantages and has its own applicability. next I will talk about these color modes RGB, CMYK, LAB, HSB ...... Many friends may have seen these color patterns, but do you know about them? Most of my friends will say they don't know. Color pattern is the most basic knowledge of graphic design. how can this problem be solved? Each mode has its own advantages and disadvantages and has its own applicability. next I will talk about these color modes in detail. 1. RGB mode

RGB is the color mode of the color light. R represents Red, G represents Green, and B represents Blue. The three colors are superimposed to form other colors. Because the three colors have 256 levels of brightness, the three colors are superimposed to form 16.7 million colors. That is, true color. they can be used in the present world.

In RGB mode, colors such as red, green, and blue are superimposed to generate their colors. Therefore, this mode is also called the coloring mode. All monitors, projection devices, televisions, and many other devices depend on this coloring mode.

In terms of image editing, the RGB color mode is also the best color mode, because it provides a 24-bit color range for the full screen, that is, true color display. However, it is not optimal to use the RGB mode for printing, because some colors provided by the RGB mode are out of the print range, so when printing a true color image, it will inevitably lose some of the brightness, and the bright colors will be distorted .. This is mainly because the CMYK mode is used for printing, while the CMYK mode defines much less color than the RGB mode. Therefore, when printing, the system automatically converts the RGB mode to the CMYK mode, which will inevitably cause loss of some colors and distortion after printing.

2. CMYK mode

When the sun shines on an object, the object will absorb a part of the light and reflect the remaining light. the reflected light is the color of the object we see. This is a color reduction mode, and it is also fundamentally different from the RGB mode. Not only do we use this fading mode when we look at the color of an object, but it is also used for printing on paper.

According to this fading mode, the suitable printing CMYK color mode is developed.

CMYK represents four colors used for printing. C represents cyan, M represents magenta, Y represents yellow, and K represents black. In actual reference, it is difficult to combine cyan, magenta, and yellow to form a true black, but it is only Brown at most. Therefore, K-black is introduced. Black is used to strengthen the dark tone and deepen the dark color.

The CMYK mode is the best printing mode. the RGB mode cannot be completely printed even if there are many colors. Is CMYK used during editing? No, for the following reasons:

Editing in CMYK mode can avoid color loss, but the operation speed is very slow. This is mainly because: 1. even if you work in CMYK mode, Photoshop must convert the CMYK mode to the RGB mode used by the display. 2. for the same image, the RGB mode only needs to process three channels, while the CMYK mode needs to process four feeds? /P>

Because the scanners and monitors used by users are both RGB devices, the conversion of the RGB mode to the CMYK mode is a process in any case of the "MYK" mode.

Therefore, whether to use the CMYK mode for editing is a problem of converting the RGB mode and the CMYK mode.

I would like to give a suggestion here, which is also a bit of my experience. Edit in RGB mode, print in CMYK mode, convert before printing, and add necessary color correction, sharpening, and rest. In this way, although Photoshop is slower in CMYK mode, it can save most of the editing time.

To quickly Preview the display effect of the CMYK mode image, you can use the CMYK Preview (CMYK Preview) command under the View menu without converting the mode.

This mode conversion before printing is not the best way to avoid Image loss. The best way is to combine the Lab mode and the CMYK mode to minimize image distortion. The following describes the Lab mode.

3. Lab mode

The Lab model was developed by the international lighting commission (CIE) in 1976 (wow, it's far away .) A published color model.

You have understood that the RGB mode is a color adding mode for the luminous screen, and the CMYK mode is a color-reflective printing mode. So what processing mode does Lab have?

The Lab model neither depends on light nor paint. it is a color model determined by the CIE organization, which theoretically includes all colors visible to the human eye. The Lab mode makes up for the shortcomings of the RGB and CMYK color modes.

The Lab mode consists of three channels, but not R, G, and B. One of its channels is brightness, that is, L. The other two are color channels, represented by A and B. Channel A includes colors from dark green (base brightness value) to Gray (center brightness value) to bright pink (high brightness value); channel B is from bright blue (bottom brightness value) to Gray (moderate brightness) to yellow (high brightness ). Therefore, this mixture of colors will produce bright colors.

The Lab mode has the most colors defined, is independent of light and equipment, and the processing speed is as fast as the RGB mode, much faster than the CMYK mode. Therefore, you can use the Lab mode in image editing with confidence. In addition, the color is not lost or replaced when the Lab mode is switched to CMYK mode. Therefore, the best way to avoid color loss is to apply the Lab mode to edit the image and then convert it to the CMYK mode to print the output.

When you convert the RGB mode to the CMYK mode, Photoshop automatically converts the RGB mode to the Lab mode and then to the CMYK mode.

In terms of the color range, the first is the Lab mode, the second is the RGB mode, and the third is the CMYK mode.

4. HSB mode

After introducing the three main color modes, we will introduce another color mode, the HSB color mode, which will only appear in the color drawing window.

In HSB mode, H indicates the color phase, S indicates the saturation, and B indicates the brightness.

Color: solid color, that is, the color of the visible spectrum. The red color is 0 degrees, the green color is 120 degrees, and the blue color is 240 degrees. It is basically a pie chart with full color in RGB mode.

Saturation: indicates the purity of the color. if it is 0, the color is used. White, black, and other gray colors have no saturation. At the maximum saturation, each color has the most pure color.

Brightness: bright reading of colors. If it is 0, it is black. The maximum brightness is the most colorful state.

5. Indexed mode

The Indexed mode is the index color mode, also called the ing color. In this mode, only one 8-bit color depth file can be stored, that is, up to 256 colors, and the colors are pre-defined. All colors of an image are defined in its image file, that is, all colors are mapped to a color disk. this is called a color comparison table. Therefore, when an image file is opened, the color comparison table is also read into Photoshop, and Photoshop finds the final color value from the color comparison table.

6. GrauScale mode

After introducing the colorful world, we are now in the gray world. In fact, Gray is also a kind of color, but also has a beautiful side.

Grayscale files are 8-bit images that can form up to 256 levels of gray scale. brightness is the only factor for controlling gray scale. The brightness is about high. The lighter the gray scale, the closer it is to white. the deeper the brightness, the closer it is to black. Therefore, black and white are included in the gray scale, which is a subset of the gray mode.

GrauScale mode

And grayscale mode. Only grayscale exists in grayscale mode. When a color file is converted to a grayscale file, all color information will be removed from the file. Although Photoshop allows converting a grayscale file to a color file, it is impossible to restore the original color.

In the grayscale file, the color saturation of the image is 0, and the brightness is the only option that can affect the grayscale image. Brightness is the measure of light intensity. 0% represents black and 100% represents white. The K value in the Color palette is used to measure the amount of black ink.

7. Biyesap mode

The black/white bitmap mode is an image consisting of only black and white pixels. some people think that since Black is a subset of the gray color mode, this mode is of little use. In fact, this is a wrong idea. it is precisely because of the Biyesap mode that we can better control the printing and output of grayscale images. In fact, output devices like laser printers use small points to render grayscale images. Therefore, the Biyesap mode can better set the size and shape of the dot and the angle of each other.

Note that only grayscale or multi-channel images can be converted to the Biyesap mode. a dialog box is displayed, where you can set the output resolution and conversion mode of the file. The specific settings are as follows:

Output: the resolution of a black-and-white image.

Method: provides the following five settings.

50% Threshold (critical value): If this option is selected, grayscale pixels greater than 50% will become black, while grayscale images smaller than or equal to 50% will become white.

Pattern Dither (image jitter): uses random black and white pixels to shake the image. The image generated using this method is ugly, and there is almost no gap between pixels.

Diffusion Dither: This option is used to generate a metallic effect. It will adopt a divergence process to change a pixel to a monochrome, and this result is a particle effect.

Halftone Screen: This conversion makes the image look like a gray image printed on a semi-color Screen.

Custom Pattern: This conversion method allows you to add a Custom Pattern (a Pattern defined by the Edit m Pattern command in the Edit menu) to a bitmap image.

Please note that after the image is converted to the Biyesap mode, it cannot be edited or even restored.

8. Duotone

Duotone mode uses a gray-scale ink or color ink to render a gray-scale image. it is a dual-color overprint or same-color thick-light overprint mode. In this mode, you can add up to four colors to the grayscale image, so that you can print an image that looks much better than the pure gray mode.