Dpi refers to pixels per inch, which is the scanning accuracy. The international practice is to calculate the number of pixels in an area of one square inch. The smaller the dpi, the lower the definition of scanning.

Dpi accuracy:

The DPI parameter refers to how many "dots" the mouse cursor can move on the screen when the mouse moves 1 inch on the desktop.

In fact, the concept of DPI can't express the accuracy of the mouse more accurately and uniquely. For example, the number of dots per inch is not constant on the screen. It is affected by resolution and other factors, so it is not the only pixel on the screen. It is possible that this point is 4 pixels or 1 pixel. This is because the concept of DPI involves the change of display.

The more scientific and accepted new standard is to use CPI to express mouse accuracy. The explanation of this concept is: the number of mouse samples per inch. To be clear, it is how many points can be collected from the moving surface when the mouse moves one inch. This property is completely related to the performance of the mouse itself, and no longer involves the problem of the display.

Extended data:

Basic technology of dpi:

DPI (Deep Packet Inspection) technology is a traffic detection and control technology based on application layer. When IP packets, TCP or UDP data streams pass through the bandwidth management system based on DPI technology.

By deeply reading the contents of IP packet payload, the system reorganizes the application layer information in the OSI seven-layer protocol to get the content of the whole application program, and then shapes the traffic according to the management strategy defined by the system.

The bandwidth management solution based on DPI technology is similar to the well-known antivirus software system in some respects, that is, the application type it can identify must be known to the system. Take BT, which users are familiar with, as an example, and its handshake protocol feature word is ".

BitTorrent protocol "; In other words, the anti-virus system should have a huge virus feature library in the background, and the bandwidth management system based on DPI technology should also maintain an application feature library.

When the traffic passes, the application type is determined by comparing the unpacked application information with the background feature database; When new applications appear, the background application feature database should be updated to have the ability to identify and control new applications.