How are camera pixels calculated?

A pixel can be represented by a number.

Pixels can be represented by a number, such as a digital camera with 300,000 pixels, rated at 300,000 pixels; It can also be represented by a pair of numbers, such as a 640x480 display, which represents 640 pixels horizontally and 480 pixels vertically, so its total number is 640x480 = 307200 pixels.

For example, when 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.

Extended data:

Pixels are units used to calculate digital images. Like photographs, digital images have continuous shadows. If you enlarge the image several times, you will find that these continuous shadows are actually composed of many small squares with similar colors.

These small squares are the smallest individual pixels that make up an image. This smallest graphic unit can usually display a coloring point on the screen. The higher the pixel, the richer the sample and the more realistic the color is. Pixel is usually considered as the smallest complete sample of an image. This definition is very relevant to the context.

Baidu encyclopedia-pixel