What does the pixel size in PS mean? How did you work it out?

Pixel is the most basic unit of an image. It is a square small color block. An image usually consists of many pixels, which are arranged in rows or columns, and each pixel is square. When you use the zoom tool to enlarge the image large enough, you can see a mosaic-like effect, and each small square is a pixel.

The size of each point in a computer is determined by the number of colors. By default, all RGB 8 bits are used, that is, each color in RGB is 8 bits, and a * * * needs 24 bits of storage, and dividing by 8 is 3 bytes. The pixel size of an image is the size of the storage space occupied by the image.

Extended data

When the picture size is in pixels, we need to specify its fixed resolution in order to convert the picture size into the actual size in reality. For example, the resolution of the most commonly used pictures in web pages is 72, that is, 7265438 pixels per inch +0 inch equals 2.54 cm, then it can be concluded that each cm equals 28 pixels through conversion; Another example is a picture with the length of 15x 15cm, which is equal to the length of 420*420 pixels.

Graphics of 256 colors or less are usually stored in a block or plane format in a video memory, where each pixel in the video memory is an index value of a color array called a palette. Therefore, these patterns are sometimes called index patterns.

Although there are only 256 colors at a time, these 256 colors are selected from a much larger palette, usually 16 megacolors. You can get the animation effect by changing the color values in the palette. 95(windows95 and 98(windows98' s logos is probably the most famous example of this kind of animation.

For depths exceeding 8 bits, these numbers are the sum of three components (red, green and blue). The depth of 16 is usually divided into 5 bits of red, 5 bits of blue and 6 bits of green (eyes are more sensitive to green).

The depth of 24 bits is usually 8 bits per component. In some systems, 32-bit depth is also optional: this means that a 24-bit pixel has 8 extra numbers to describe transparency. In the old system, 4bpp( 16 color) is also very common. When an image file is displayed on the screen, the number of bits per pixel may be different for raster text and display. Some raster image file formats have greater color depth than others.

For example, the maximum depth of GIF format is 8 bits, while TIFF files can handle 48-bit pixels. No display can display 48-bit colors, so this depth is usually used for special professional applications, such as film scanners and printers. This file is drawn at a depth of 24 bits on the screen. Pixels are only one of the conditions that determine clarity. A camera can use a resolution of 2048× 1536 pixels, which is usually called "31million pixels" (2048×1536 = 3145728).

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