A Bottom-Up Design Approach of Critically Sampled Contourlet Transform for Efficient Image Representation
A Bottom-Up Design Approach of Critically Sampled Contourlet Transform for Efficient Image Representation
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DOI：
10.1587/transfun.e92.a.762
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发表时间：
2009-03
期刊：
影响因子：
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通讯作者：
Seisuke Kyochi;Shizuka Higaki;Yuichi Tanaka;M. Ikehara
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文献类型：
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作者：
Seisuke Kyochi;Shizuka Higaki;Yuichi Tanaka;M. Ikehara
提出了一种新的临界采样轮廓波变换（CSCT）设计方法。原始CT由拉普拉斯金字塔和方向滤波器组组成，为图像表示提供了有效的频率平面划分。但由于其过完备性不适合图像编码等应用，近年来人们对其临界采样版本进行了研究。虽然已经提出了几种类型的CSCT，但它们在实现上存在问题，或者存在与原始CT不同的频率平面划分不自然的问题。与传统的基于“自上而下”方法的设计方法不同，本文提出的方法是基于“自下而上”的设计方法。即，本文提出的CSCT将频率平面分解为小的方向子带，然后将它们合成为目标频率平面分区，而传统的子带则直接分解为目标频率平面分区。通过这种方式，所提出的CSCT可以设计出与原始CT相同的高效分频算法，从而实现图像的表示。本文通过非线性近似仿真验证了该方法的有效性。
In this paper, a novel design method of critically sampled contourlet transform (CSCT) is proposed. The original CT which consists of Laplacian pyramid and directional filter bank provides efficient frequency plane partition for image representation. However its overcompleteness is not suitable for some applications such as image coding, its critical sampling version has been studied recently. Although several types of the CSCT have been proposed, they have problems on their realization or unnatural frequency plane partition which is different from the original CT. In contrast to the way in conventional design methods based on a “top-down” approach, the proposed method is based on a “bottom-up” one. That is, the proposed CSCT decomposes the frequency plane into small directional subbands, and then synthesizes them up to a target frequency plane partition, while the conventional ones decompose into it directly. By this way, the proposed CSCT can design an efficient frequency division which is the same as the original CT for image representation can be realized. In this paper, its effectiveness is verified by non-linear approximation simulation.