3.1 概述 3.2 可分离图像变换 3.3 离散傅里叶变换和性质 3.4 快速傅里叶变换 3.5 离散沃尔什变换 3.6 离散余弦变换 3.7 小波变换 -3.1 overview 3.2 detachable image transform 3.3 Discrete Fourier Transform and Fast Fourier Transform 3.4 Properties 3.5 Discrete Walsh Transform 3.6 Discret

some fast feature extraction algorithms are addressed for joint retrieval of images compressed in JPEG and JPEG2000 formats. In order to avoid full decoding, three fast algorithms that convert block-based discrete cosine transform (BDCT) into wav