ldpc码的编解码实现，实现了图像的加水印，去噪，加噪声等功能，IMC-PID是利用内模控制原理来对PID参数进行计算。- Codec ldpc code implementation Realize image watermarking, de-noising, plus noise and other functions, The IMC- PID is using the internal model control principle for PID parameters is calculated.