نتایج جستجو برای: fast discrete curvelet transform

تعداد نتایج: 471537  

2014
A. Anilet Bala

A new image denoising method based on curvelet transform is proposed. The limitations of commonly used separable extensions of one-dimensional transforms, such as the Fourier and wavelet transforms, in capturing the geometry of image edges are well known. Here, we pursue "true" two-dimensional transform that can capture the intrinsic geometrical structure that is key in visual information. Deno...

2010
Ji Shen

In this paper, we propose a new no-reference VQA metric, called Video Hybrid No-reference (VHNR) method. It is based on natural video statistics built from the coefficients of 3D curvelet and cosine transforms. VHNR can blindly predict the quality of noisy, blurry, or MPEG2 compressed videos and requires no original reference video. The 3D curvelet transform is known to be sensitive to surface ...

2013
Liang Xu Junping Du Qian Hu Qingping Li

The uniform discrete curvelet transform (UDCT) is a novel tool for multiscale representations with several desirable properties compared to previous representation methods. A novel algorithm based on UDCT is proposed for the fusion of multi‐source images. A novel fusion rule for different subband coefficients obtained by UDCT decomposition is discussed in detail. Low‐pass ...

In this article a new method is introduced for distinguishing roots and background based on their digital curvelet transform in minirhizotron images. In the proposed method, the nonlinear mapping is applied on sub-band curvelet components followed by boundary detection using energy optimization concept. The curvelet transform has the excellent capability in detecting roots with different orient...

2014
P. AFROZ KHAN

In this paper, an automatic support system for brain tumor stage classification using learning machine and for detecting brain tumor during early stages using fuzzy clustering methods is proposed. The fuzzy clustering method is a segmentation technique presented to segment the Magnetic Resonance images for detecting the Brain Tumor during early stages and for examining anatomical structures. Fa...

Journal: :IEEE transactions on image processing : a publication of the IEEE Signal Processing Society 2001
Emmanuel J. Candès

We describe 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. A central tool is Fourier-domain computation of an approximate digital Radon transform. We introduce a very simple ...

2007
Tanaya Mandal Angshul Majumdar Q. M. Jonathan Wu

This paper proposes a new method for face recognition based on a multiresolution analysis tool called Digital Curvelet Transform. Multiresolution ideas notably the wavelet transform have been profusely employed for addressing the problem of face recognition. However, theoretical studies indicate, digital curvelet transform to be an even better method than wavelets. In this paper, the feature ex...

2011
ANTON A. DUCHKOV STEVEN DONG FREDRIK ANDERSSON MAARTEN V. DE HOOP

We revisit Smith’s frame of curvelets and discretize it making use of the USFFT as developed by Dutt and Roklin, and Beylkin. In the discretization, we directly approximate the underlying dyadic parabolic decomposition, its (rotational) symmetry, and approximate all the necessary decay estimates in phase space with arbitrary accuracy. Numerically, our transform is unitary. Moreover, if we apply...

Journal: :Optics letters 2012
Yijin Liu Junyue Wang Youli Hong Zhili Wang Kai Zhang Phillip A Williams Peiping Zhu Joy C Andrews Piero Pianetta Ziyu Wu

A fast discrete curvelet transform based focus-stacking algorithm for extending the depth of focus of a transmission x-ray microscope (TXM) is presented. By analyzing an image stack of a sample taken in a Z-scan, a fully in-focus image can be generated by the proposed scheme. With the extended depth of focus, it is possible to obtain 3D structural information over a large volume at nanometer re...

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