Talk about Photoshop's many color modes (2)

After introducing the three main color modes, we now introduce another color mode, the HSB color mode, which appears in the color capture window.

In the HSB mode, H represents hue, S represents saturation, and B represents luminance.

Hue: A solid color, that is, a single color that makes up the visible spectrum. Red is at 0 degrees, green at 120 degrees, and blue at 240 degrees. It is basically a full-color pie chart of RGB mode.

Saturation: Indicates the purity of the color. When it is 0, it is a color. White, black, and other gray colors have no saturation. At maximum saturation, each hue has the purest shade.

Brightness: Bright reading of colors. When it is 0, it is black. The maximum brightness is the most vivid color.

5, Indexed mode

Indexed mode is the index color mode, also known as the mapped color. In this mode, only 8bit color depth files can be stored, ie up to 256 colors, and the colors are predefined. All colors of an image are defined in its image file. That is, all colors are mapped into a color disk. This is called a color map. Therefore, when the image file is opened, the color comparison table is also read into Photoshop. Photoshop finds the final color value from the color table.

6, GrauScale mode

After introducing the brilliant color world, it is now entering the gray world. In fact, gray is also a kind of color, but also has a brilliant side.

Grayscale files are 8-bit images that can form up to 256 shades of gray, and brightness is the only element that controls grayscale. The brightness is about high, the lighter the gray, the closer to white; the darker the brightness, the darker the gray, the closer to black. Therefore, black and white are included in grayscale and they are a subset of the grayscale mode.

Only grayscale exists in grayscale mode. When a color file is converted to a grayscale file, all color information is removed from the file. Although Photoshop allows you to convert a grayscale file to a color mode file, it is not possible to restore the original color without any change.

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 a measure of light intensity, with 0% representing black and 100% representing white. The value of K in the Color palette is used to measure the amount of black ink.

7, Bitmap mode

The black and white bitmap mode is an image consisting of only black and white pixels. Some people think that since black is a subset of the grayscale color mode, this mode is not very useful. In fact, this is a misunderstanding. It is precisely because of the Bitmap mode that it is possible to more perfectly control the printout of grayscale images. In fact, output devices such as laser printers rely on tiny dots to render grayscale images. Therefore, Bitmap mode can be used to better set the size, shape, and angle of the dots.

It should be noted that only grayscale images or multichannel images can be converted to Bitmap mode. A dialog will appear where you can set the output resolution and conversion method of the file. The specific setting method is as follows:

Output: refers to the resolution of the black and white image.

Method: Provides the following 5 settings.

50% Threshold: When selected, more than 50% of grayscale pixels will turn black, and less than or equal to 50% of grayscale images will turn white.

Pattern Dither: Use some random black and white pixels to dither the image. Images generated using this method are ugly and there are few gaps between the pixels.

Diffusion Dither: Use this item to generate a metal plate effect. It will use a divergence process to change one pixel to a single color. The result is a particle effect.

Halftone Screen: This conversion makes the image look like a grayscale image printed on a halftone screen.

Custom Pattern: This conversion method allows a custom pattern (pattern defined with the Custom Pattern command in the Edit menu) to be added to a bitmap image.

Please note that when the image is converted to Bitmap mode, no other editing is possible, and even the image in grayscale mode cannot be restored.

8, Duotone color set mode

Duotone mode uses a grayscale ink or color ink to render a grayscale image in two-color overprint or isochromatic contrast mode. In this mode, up to four colors can be added to the grayscale image, so that you can print much better looking images than the simple grayscale mode.