负责把图片转换格式的Java代码

本代码的格式是由其他的格式转换成PNG格式

可以可以根据自己的需求改换代码，代码比较粗糙，只实现了基本功能，可以运行-Responsible for the image conversion format Java code in this code format is the format from other formats can be converted into PNG can change according to their own needs code, code of rough comparison, only the realization of the basic functions, you can run