半色调技术中，调频加网的生成主要有Bayer 、Floyd-Steinberg、绿噪声等加网方式，本代码主要针对经典的Bayer算法进行编程和调用。(The main generation of FM screen are Bayer, Floyd-Steinberg, green noise and other network mode. This code is mainly for the classic Bayer algorithm programming and call.)