Portable Network Graphics (PNG) is a graphic file format. The files are compressed with a selectable compression factor, and, as opposed to the JPG format, PNG files are always compressed without any information loss.
可移植网络图形 (PNG) 是一种图形文件格式。这种文件可使用一种可选的压缩系数来进行压缩，与 JPG 格式相比，PNG 文件的压缩不会造成任何信息丢失。