What color modes are there?

Question 1: What are the common image color modes? The color information of image pixels in the computer must be converted into binary numbers for storage, and several binary numbers are used to form an image with a bit depth. The greater the bit depth, the more colors can be represented. Color mode provides a method to convert colors into digital data, so that colors can be described continuously in various media and can be used across platforms, such as from monitors to printers and from Mac to PC. Color mode is a problem involved in all graphics and image processing software. Common color modes include bitmap mode, gray gray mode, Duotone two-color mode, index color mode, RGB color mode, CMYK color mode, Lab color mode, multi-channel multi-channel mode and HSB color mode. 1. Bitmap Bitmap mode Bitmap mode, also called black and white mode, is the simplest color mode and belongs to achromatic color mode. Bitmap mode image is only black and white and consists of 1 bit pixels, and each pixel is represented by 1 bit binary number. Files occupy little storage space. Generally, bitmap mode is not selected when designing and making, unless there is a special purpose. Only two-color mode and gray mode can be converted to bitmap mode. 2. Gray-scale gray-scale mode The gray-scale mode image has no color information, and the color saturation is 0, which belongs to achromatic color mode. The image consists of 256 gray levels between black and white. Because the gray image has only one brightness channel, the storage space occupied by the gray mode image file is also very small. When the bitmap mode image is converted to gray mode, the gray image has only one gray level. If the size ratio is 1, the black-and-white image is still the same, but the image is reduced. 3.Duotone two-tone mode Duotone two-tone mode is a mode related to printing, which is developed from gray mode. Create two-color (2-color), three-color (3-color) or four-color (4-color) gray images with 1 ~ 4 kinds of custom gray inks or color inks. In the two-tone image, color ink is only used to generate color gray, not to regenerate different colors, which is a special technology in the printing field. In fact, the two-tone mode image has only one 8-bit brightness channel, but the color information selected by the user and the corresponding intensity curve are additionally recorded on the brightness value. When images of other color modes need to be converted to the two-tone mode, they must be converted to the gray mode first, and then converted to the two-tone mode. 4. indexed color mode indexed color mode only supports 8-bit colors, and the color table predefined by the system contains at most 256 typical colors to represent color images. If you choose different color table options, such as ink body, gray scale and color spectrum, the image display effect will be different. Because the indexed color mode image is only 8 bits deep, the image file also occupies a small storage space. Indexed color mode images are mainly used for network, game making and screen printing images. 5.RGBRGB color mode adopts three-color mode, also known as additive color mode, which is the most commonly used basic color mode in image software at present. Many light source imaging devices, such as monitors, projectors, televisions, scanners and digital cameras, also work in RGB additive mode. Its basic characteristics come from the light in nature, and the three primary colors of red, green and blue are mixed in different proportions to form the color of visible spectrum. RGB color mode is a color mode generated by the superposition of red, green and blue channels, forming color information with a depth of 24 bits. Therefore, the combination of three color channels produces more than 65,438+06.7 million (2,563) colors, which is enough to display a complete color image, as shown in Figure 65,438+0-25. If the RGB image is 16 bits per channel and forms color information with a depth of 48 bits (16× 3), it has the ability to express more colors and the image is more delicate and realistic. Of course, files will take up more storage space. 6.CMYK color mode CMYK color mode adopts printing three-color mode, also known as subtractive color mode. Most graphic image software supports this color mode, which is a proprietary mode used by printing, printing and other ink imaging equipment, that is, printing field. Its basic feature is based on the light absorption characteristics of ink on printed matter, that is, when light strikes the ink, part of the light is absorbed and part of the light is reflected back to the eyes. Theoretically, cyan, magenta, magenta and yellow pigments can be synthesized in different proportions. & gt

Question 2: What color modes are there in 2:PS? 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, the superposition of red, green and blue can produce other colors, so this mode is also called additive mode. Many devices, such as monitors, projection devices and televisions, rely on this additive mode.

2.CMYK mode

CMYK mode is a color mode composed of four basic colors: cyan, megacolor, yellow and black. This is a subtractive color mode. This subtractive color mode is applied in printing and printing.

3. Laboratory mode

Lab mode consists of three channels, one of which is brightness, that is, L, and the other two are color channels, which are denoted by A and B respectively. The color of channel A ranges 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 the lab mode, colors will be mixed to produce bright colors. The model was published by CIE in 1976.

4.HSB mode

In HSB mode, H stands for hue, S stands for saturation and B stands for 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, and it is gray when it is 0. White, black and other grays have no saturation. Brightness: It is the brightness of the color. It is black when it is 0.

5. Index mode

The index mode is indexed color mode, also known as * * * color. In this mode, only one file with 8-bit color depth can be stored, that is, up to 256 colors. 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. Gray mode

Gray scale mode has only gray scale, including 256 different shades of gray from black to white. In the grayscale file, the color saturation of the image is 0, and brightness is the only option that can affect the grayscale image. When a color file is converted into a grayscale file, all the color information in the file will be deleted. Photoshop allows you to convert grayscale files into color mode files, but it can't restore the original color unchanged.

7. Bitmap mode

The black-and-white bitmap mode is an image composed of only black-and-white pixels. Please note that only grayscale images or multichannel images can be converted to bitmap mode. After the image is converted into bitmap mode, other editing cannot be performed, and even the image in gray mode cannot be restored.

8. Two-tone and two-color setting mode

Two-tone mode uses gray ink or color ink to render gray images, which is a two-color overprint or the same color overprint mode.

Question 3: What are the differences between various color modes in 3:PS? 1.RGB color mode.

This is the most commonly used mode in Photoshop, also known as true color mode. The image displayed in RGB mode has the highest quality. So it has become the default mode of Photoshop, and many effects in Photoshop need to be in RGB mode to take effect. The RGB color mode is mainly composed of three basic colors of R (red), G (green) and B (blue), forming three color channels of red, green and blue. Each color channel contains 8-bit color information, and each information is represented by a brightness value of 0~255, so these three channels can produce more than16.7 million different colors together. Therefore, when printing an image, you cannot print an image in RGB mode. At this time, it is necessary to change the RGB mode image to CMYK mode. If an image in RGB mode is converted, color loss or color cast may occur.

Second, HSB mode.

The establishment of HSB mode is mainly based on the way of human perception of color. The human eye can't distinguish the proportion of each primary color in RGB mode, but can only distinguish the color type, saturation and intensity. According to this characteristic of human eyes, the color of HSB forms an intuitive method, which can be directly distinguished by human eyes. It mainly regards color as composed of hue, saturation and lightness. Among them, these three elements all describe different meanings. For example, hue refers to different characteristics given by different wavelengths, such as red and green have different hue values; Saturation refers to the depth of color, that is, the relative purity of a single pigment, such as red can be divided into deep red, magenta, light red and so on; Brightness is used to express the intensity of color and describes the ratio of the amount of reflected light to the amount of absorbed light. Click the horizontal black triangle in the upper right corner of the Color Function panel and select the HSB slider from the pop-up menu. One thing to note here is that the HSB mode is represented by an angle of 0-360 degrees, rather than a percentage as we understand it, just like a large colored wind wheel. Every time it rotates a little, its color changes according to this circumferential angle.

Thirdly, CMYK color mode.

This is also a common color pattern. When printing an image, its color mode must be converted to CMYK mode. Therefore, this mode is mainly used for industrial printing. The CMYK pattern is matched by subtracting four colors: C (cyan), M (magenta), Y (yellow) and K (black). Therefore, four channels of cyan, magenta, yellow and black are formed, and each channel is mixed to form a variety of colors. It is worth noting that if these four solid colors are included in the printing, they must be 100% solid colors. For example, if black is not set to pure black when printing, the film will not be sent successfully when printing, that is, the image cannot be printed. Because many of Photoshop's filter effects can't be used in CMYK mode, RGB mode is generally used, and it will only be converted to CMYK mode when printing is about to start, and the color may change.

Fourth, the gray model.

The image in grayscale mode has only grayscale and no other colors. Each pixel is represented by 8-bit or 16-bit color. If the color image is converted to grayscale mode, all colors will be replaced by different grayscales.

Verb (abbreviation for verb) bitmap mode

Bitmap mode uses black and white to represent the image, without gray and other colors, so it is also called black and white image. If you convert an image to bitmap mode, you should first convert it to grayscale mode.

Six, two-tone mode

As mentioned above, CMYK mode is always used in printing, that is, four-color mode, but sometimes images only contain two colors and their matching colors, so in order to save costs, two-color mode can be used.

Seven. Laboratory color mode

Lab color mode is the built-in mode of Photoshop, and it is also the mode with the widest color range among all modes. Therefore, when converting RGB and CMYK modes, the system will first convert to Lab mode, and then convert to CMYK color mode. But in general, Lab color mode is rarely used. Lab mode consists of three channels: brightness (L), a (from green to red) and b (from blue to yellow). Where the values of a and b are-120...> & gt

Question 4: What are too many commonly used color modes in 4:PS? At least three are simple RGB mode, CMYK mode, HSB mode, Lab color mode, bitmap mode, gray mode, indexed color mode, two-tone mode and multi-channel mode.

Question: What is the default color mode of photoshop? There is no breach of contract. When you create a new color pattern, you can choose your own color pattern. The most commonly used color modes are RGB (Display Color Mode) and CMYK (Print Color Mode).

There are basic color modes in PS, such as RGB mode, CMYK mode, HSB mode, Lab color mode, bitmap mode, gray mode, index color mode, two-tone mode and multi-channel mode.

Question 6: What is the RBG color mode? RBG color mode and jpg image format are different concepts.

Color mode refers to the color display mode of the picture. In addition to RGB, there are also color modes commonly used by CMYK. The former uses the superposition of red (R), green (G) and blue (B) to realize color display, while the latter uses the superposition of cyan (C), magenta (M), yellow (Y) and black (K) to realize color display.

Picture format is a way to only store or compress pictures, such as BMP/JPG/GIF.

The color mode and picture format can be converted by PS, and the picture format can also be converted by the drawing tool that comes with windows (just save it with the drawing tool).

Question: What color modes does photoshop have? What is the difference? RGB, CMYK, LAB, HSB…… ... Many friends may have seen these color patterns, but do you know them? Most of my friends will not understand. Color pattern is the most basic knowledge of graphic design. What if you don't master it? Each model has its own advantages and disadvantages and scope of application. Let me talk about these color patterns in detail.

1, RGB mode

RGB is the color mode of colored light. R stands for red, G stands for green, B stands for blue, and the three colors are superimposed to form other colors. Because all three colors have 256 brightness levels, the three colors are superimposed to form16.7 million colors. That is, the true color, through which it can be used in a beautiful world.

In RGB mode, the superposition of red, green and blue can produce other colors, so this mode is also called additive mode. All monitors, projection devices, televisions and many other devices rely on this additive mode.

In terms of editing images, RGB color mode is also the best color mode, because it can provide a full-screen color range of 24bit, that is, true color display. However, if you use RGB mode to print, it is not the best, because some colors provided by RGB mode are beyond the printing range, so you will lose some brightness when printing true color images, and brighter colors will be distorted. . This is mainly because printing uses CMYK mode, and the colors defined by CMYK mode are much less than those defined by RGB mode. Therefore, when printing, the system will automatically convert RGB mode to CMYK mode, and some color loss and distortion will inevitably occur after printing.

2.CMYK mode

When sunlight shines on an object, the object will absorb part of the light and reflect the rest. Reflected light is the color of the object we see. This is a subtractive color mode, which is also a fundamental difference from RGB mode. We use this subtractive mode not only when we look at the color of an object, but also when we print on paper.

According to this subtractive color mode, a CMYK color mode suitable for printing is developed.

CMYK stands for four colors used in printing, C stands for cyan, M stands for magenta, Y stands for yellow and K stands for black. Because in practical reference, it is difficult for cyan, magenta and yellow to form real black, and at most it is brown. So k black was introduced. The role of black is to strengthen the dark tone and deepen the dark color.

CMYK mode is the best printing mode, while RGB mode can't be printed completely despite many colors. So do you use CMYK mode when editing? No, for the following reasons:

Although editing in CMYK mode can avoid fading, the operation speed is very slow. Mainly because: 1, even when working in CMYK mode, Photoshop must change CMYK mode to RGB mode used by the display. 2. For the same image, RGB mode only needs to process three channels, while CMYK mode needs to process four channels (the computer speed here is not what it was in 2000).

Because the scanner and monitor used by users are both RGB devices, whenever they work in CMYK mode, there is a process of converting RGB mode to CMYK mode.

Therefore, whether to edit in CMYK mode becomes a conversion problem between RGB mode and CMYK mode.

Here is a suggestion, which is my experience. First edit in RGB mode, then print in CMYK mode, then convert before printing, and then add necessary color correction, sharpening and rest. Although this makes Photoshop slower in CMYK mode, it can save most editing time.

In order to quickly preview the display effect of an image in CMYK mode without changing the mode, you can use the CMYK Preview (CMYK command under the View menu.

This mode conversion before printing is not the best way to avoid image loss. The best way is to combine Lab mode with CMYK mode, which can minimize image distortion. The following describes the laboratory mode.

3. Laboratory mode

The laboratory model was established by CIE in 1976 (wow, how far it is. ) released a color mode.

You have understood ... >>

Question 8: About PS! What color pattern is the poster made of? Four-color separation for printing

8-bit

Standard print setting: 300dpi/ inch

Bleeding: 3 mm

Question 9: Please explain what the color mode of the image in PS means.

A model that represents a certain color as a digital form, or a method of recording the color of an image. Divided into: RGB mode, CMYK mode, HSB mode, Lab color mode, bitmap mode, gray mode, index color mode, two-tone mode and multi-channel mode.

RGB color mode

Although the wavelength of visible light has a certain range, we don't need to represent each wavelength separately when dealing with colors. Because all colors in nature can be obtained by the combination of different intensities of red, green and blue (RGB) wavelengths, this is the principle of tricolor that people often say. So these three kinds of light are often called three primary colors or three primary colors. Sometimes we also call these three primary colors additive colors, because when we add light with different wavelengths together, we will get brighter colors. Overlapping the three primary colors alternately produces sub-mixed colors: cyan, magenta and yellow. This also leads to the concept of complementary colors. Primary colors and secondary mixed colors are complementary colors, that is, the colors that are the most different from each other. For example, cyan is composed of blue and green, while red is a missing color, so cyan and red are complementary colors to each other. In digital video, the 8-bit coding of RGB three primary colors constitutes about 167000 colors, which is what we often call true color. By the way, TV sets and computer monitors create their colors based on RGB color patterns.

CMYK mode

CMYK color mode is a printing mode. Among them, four letters refer to cyan, magenta, yellow and black respectively, representing four colors of ink in printing. There is no difference between CMYK mode and RGB mode in essence, but the principle of color generation is different. In RGB mode, color is produced by mixing light emitted by light sources, while in CMYK mode, color is produced by light shining on paper with different proportions of C, M, Y and K inks, and part of the spectrum is absorbed and reflected to human eyes. Because when C, M, Y and K are mixed, with the increase of C, M, Y and K, less and less light will be reflected to human eyes, and the brightness of light will be lower and lower. All methods of generating colors in CMYK mode are also called color light subtraction.

HSB color mode

From the psychological point of view, color has three elements: hue, saturation and lightness. HSB color mode is a color mode based on people's psychological feelings about color. It transforms RGB primary colors into Lab mode, and then considers people's psychological feelings about colors on the basis of Lab mode. Therefore, this color mode is more in line with people's visual experience and makes people feel more intuitive. It can be represented by two cone-shaped solid models butted at the bottom, in which the axial direction represents the brightness, and it turns from white to black from top to bottom; Radial represents color saturation, which gradually becomes higher from the inside out; In the circumferential direction, it represents the change of hue and forms a color ring.

Laboratory color mode

Lab color is converted from RGB primary colors, which is a bridge from RGB mode to HSB mode and CMYK mode. The color mode consists of brightness and two color (a, b) axes. It is represented by a circular line on the plane formed by the color axis. The change of color, in which the radial direction indicates the change of color saturation, and the saturation gradually increases from the inside out; The circumferential direction indicates the change of hue, and each circumference forms a color ring; Different luminous rates represent different brightness and correspond to different annular color-changing lines. It is a "device-independent" color mode, that is, no matter what kind of monitor or printer is used, the color of Lab will not change.

Bitmap mode

Bitmap mode uses two colors (black and white) to represent pixels in an image. Images in bitmap mode are also called black-and-white images. Because its depth is 1, it is also called a one-bit image. Because the bitmap mode only uses black and white to represent the pixels of the image, many details will be lost when the image is converted into bitmap mode, so Photoshop provides several algorithms to simulate the missing details in the image. In the case of the same width, height and resolution, the image size of bitmap mode is the smallest, which is about gray ... & gt