关键词: 小波变换, Ridgelet变换, Curvelet变换, 图像增强

Abstract: Curvelet，as a new multiscale analysis algorithm which is an extension and latest development of Wavelet and Ridgelet，is a kind of multiscale，multi-directional and anisotropic transform.The second generation Curvelet，especially the “wrapping” version of the second generation discrete Curvelet algorithm，can effectively reduce the data redundancy of the first generation Curvelet.Since the second generation curvelet has good operate speed and is geometry faithful，based on theory of image enhancement using it，this paper proposes an adaptive image enhancement algorithm through adaptively confirming noise level of Curvelet sub-bands.The experiments show that the new method has obvious advantage compared with the image enhancement based on wavelet.

Key words: wavelet transform, ridgelet transform, curvelet transform, image enhancement