How to choose the compression method?

Compression method can choose the appropriate compression method according to your own needs, such as choosing the fastest compression when the time is fast and choosing the best compression when the quality is good.

In the selection interface, fast compression provides two default compression modes, one is the fastest compression; The other is ultra-high pressure shrinkage. When the fastest compression is selected, fast compression will complete the file compression in the shortest time. However, the compression ratio of compressed files in this mode is not very high.

When ultra-high compression is selected, fast compression will compress files with ultra-high compression ratio. The compressed package created by this method will be about 10%-30% higher than other formats. In the classic mode, there is a compression mode under the general option, which can be selected from six compression modes: storage, fastest, faster, standard, better and best. You can choose the appropriate compression method according to your own needs.

Compression principle:

1. Use the algorithm to process the file lossy or lossless, so as to keep most of the information of the file and make it smaller. The basic principle of compressing a file is to find the duplicate bytes in the file and create a dictionary file with the same bytes, which is represented by a code.

2. For example, in several places in the document, using a code to represent the same word "China people * * * and China" and writing it into the "dictionary" file can achieve the purpose of file reduction.

The above contents refer to Baidu Encyclopedia-Compression.