离散余弦变换，尤其是它的第二种类型，经常被信号处理和图像处理使用，用于对信号和图像(包括静止图像和运动图像)进行有损数据压缩。有测试图片和源代码-Discrete cosine transform, in particular its second type are often used for signal processing and image processing for the signal images (including still images and moving image