이중 밀도 웨이브렛 변환의 성능 향상을 위한 Quincunx 표본화 기법

• Published in: (사)디지털산업정보학회 논문지, 8(1) Vol. 8; no. 1; pp. 171 - 181
• Main Authors: 임중희, 신종홍, Lim, Joong Hee, Shin, Jong Hong
• Format: Journal Article
• Language: Korean
• Published: (사)디지털산업정보학회 01.03.2012
• Subjects: 컴퓨터학; Shift Invariance; Quincunx; Directional Selectivity; Double-density
• ISSN: 1738-6667; 2713-9018

This paper introduces the double-density discrete wavelet transform(DWT) using quincunx sampling, which is a DWT that combines the double-density DWT and quincunx sampling method, each of which has its own characteristics and advantages. The double-density DWT is an improvement upon the critically sampled DWT with important additional properties: Firstly, It employs one scaling function and two distinct wavelets, which are designed to be offset from one another by one half. Secondly, the double-density DWT is overcomplete by a factor of two, and Finally, it is nearly shift-invariant. In two dimensions, this transform outperforms the standard DWT in terms of denoising; however, there is room for improvement because not all of the wavelets are directional. That is, although the double-density DWT utilizes more wavelets, some lack a dominant spatial orientation, which prevents them from being able to isolate those directions. A solution to this problem is a quincunx sampling method. The quincunx lattice is a sampling method in image processing. It treats the different directions more homogeneously than the separable two dimensional schemes. Proposed wavelet transformation can generate sub-images of multiple degrees rotated versions. Therefore, This method services good performance in image processing fields.