离散余弦变换(DCT)是一种常用的数字速率变换编码方法。DCT首先将整个图像分割成n×n像素块,然后在n×n像素块上逐帧执行DCT变换。由于图像的高频成分很小,与高频分量对应的系数通常为零,肉眼对高频分量的变化并不敏感, 因此,我们使会用简洁的定量方法。因此,数字传输系数的速率远小于用于传输图像像素的数字速率。到达接收机后,逆离散余弦变换返回到样本值。虽然会有一定的失真,但人眼是可以接受的。(The coefficients of the DCT domain motion compensation error or the original image information convert into blocks are represented by different frequency components. It has two advantages: first, signal 1, most of the energy in the small range is concentrated in the frequency domain. Such a descr iption is an important part of several key points. Second, mapping the frequency domain decomposition process to the human visual system.)