The nonsubsampled contourlet transform: Theory, design, and applications
The nonsubsampled contourlet transform: Theory, design, and applications
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DOI：
10.1109/tip.2006.877507
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发表时间：
2006-10-01
影响因子：
10.6
通讯作者：
Do, Minh N.
中科院分区：
文献类型：
--
作者：
da Cunha, Arthur L.;Zhou, Jianping;Do, Minh N.
本文发展了非下采样轮廓波变换（NSCT）并研究了它的应用。本文提出的结构是基于非下采样金字塔结构和非下采样方向滤波器组。其结果是一个灵活的多尺度，多方向和平移不变的图像分解，可以有效地实现通过一个槽算法。该方案的核心是不可分离的两通道非下采样滤波器组（NSFB）。我们利用不太严格的设计条件NSFB设计的过滤器，导致更好的频率选择性和规律性相比，轮廓波变换的NSCT。我们提出了一个设计框架的映射方法的基础上，允许一个快速实现的基础上的提升或梯形结构，在某些情况下，只使用一维过滤。此外，我们的设计确保了相应的框架元素是规则的，对称的，并且框架接近于紧密的框架。我们评估了NSCT在图像去噪和增强应用中的性能。在这两种应用中，NSCT与文献中的其他现有方法相比是有利的。
In this paper, we develop the nonsubsampled contourlet transform (NSCT) and study its applications. The construction proposed in this paper is based on a nonsubsampled pyramid structure and nonsubsampled directional filter banks. The result is a flexible multiscale, multidirection, and shift-invariant image decomposition that can be efficiently implemented via the a trous algorithm. At the core of the proposed scheme is the nonseparable two-channel nonsubsampled filter bank (NSFB). We exploit the less stringent design condition of the NSFB to design filters that lead to a NSCT with better frequency selectivity and regularity when compared to the contourlet transform. We propose a design framework based on the mapping approach, that allows for a fast implementation based on a lifting or ladder structure, and only uses one-dimensional filtering in some cases. In addition, our design ensures that the corresponding frame elements are regular, symmetric, and the frame is close to a tight one. We assess the performance of the NSCT in image denoising and enhancement applications. In both applications the NSCT compares favorably to other existing methods in the literature.