其变换矩阵的基向量很近似于托伯利兹矩阵的特征向量，而托伯利兹矩阵又体现了人类语言及图像信号的相关性。因此，DCT常常被认为是语音与图像信号变换的准最佳变换。-The transformation matrix of the basis vectors is approximate to the Vento Belize matrix eigenvectors, and the support matrix of Belize and reflects the relationship between human language and image signal. Therefore, DCT is often considered as a quasi optimal transformation of speech and image signal transformation.