中文说明：这是基于DCT变换的数字水印代码，将水印嵌入到中频系数中，非常适合初学者，供大家学习交流使用。
English Description：
This is based on the code of DCT digital watermarking, the watermark is embedded into the middle frequency coefficients, and is ideal for beginners, for everyone to learn to use the exchange.