A large number of gray image are created and available on the Web

since more and more gray images and digitizing tools are developed for different applications. The techniques for content-based gray image retrieval is necessary. In gray image retrieval system

we propose multiscale generic Fourier descriptor(MGFD)

which integrates generic fourier descriptor with multiscale anslysis.The experimental results show that MGFD is not only capable of multiscale anslysis

but robust against noise and other changes of image and it is also invariant to rotation and scale. It have a precise result in gray image retrieval.