Author_Institution :
California Inst. of Technol., Pasadena, CA, USA
Abstract :
Summary form only given, as follows. We present approximate digital implementations of two new mathematical transforms, namely, the ridgelet transform and the curvelet transform. Our implementations offer exact reconstruction, stability against perturbations, ease of implementation, and low computational complexity. We apply these digital transforms to the denoising of some standard images embedded in white noise. In the tests reported here, simple thresholding of the curvelet coefficients is very competitive with ´state of the art´ techniques based on wavelets, including thresholding of decimated or undecimated wavelet transforms and also including tree-based Bayesian posterior mean methods. Moreover, the curvelet reconstructions exhibit higher perceptual quality than wavelet-based reconstructions, offering visually sharper images and, in particular, higher quality recovery of edges and of faint linear and curvilinear features
Keywords :
edge detection; feature extraction; image reconstruction; transforms; white noise; approximate digital implementations; computational complexity; curvelet reconstructions; curvelet transform; curvilinear features; edges recovery; exact reconstruction; faint linear features; image denoising; mathematical transforms; perceptual quality; ridgelet transform; thresholding; white noise; Bayesian methods; Computational complexity; Image denoising; Image reconstruction; Noise reduction; Stability; Testing; Wavelet transforms; White noise;