Please use this identifier to cite or link to this item:
Title: Directionlets using in-phase lifting for image representation
Authors: Makur, Anamitra
Jayachandra, Dakala
Keywords: DRNTU::Engineering::Computer science and engineering::Computing methodologies::Image processing and computer vision
Issue Date: 2013
Source: Jayachandra, D., & Makur, A. (2014). Directionlets Using In-phase Lifting For Image Representation. IEEE Transactions on Image Processing, 23(1), 240-249.
Series/Report no.: IEEE transactions on image processing
Abstract: Directionlets allow a construction of perfect reconstruction and critically sampled multidirectional anisotropic basis, yet retaining the separable filtering of standard wavelet transform. However, due to the spatially varying filtering and downsampling direction, it is forced to apply spatial segmentation and process each segment independently. Because of this independent processing of the image segments, directionlets suffer from the following two major limitations when applied to, say, image coding. First, failure to exploit the correlation across block boundaries degrades the coding performance and also induces blocking artifacts, thus making it mandatory to use de-blocking filter at low bit rates. Second, spatial scalability, i.e., minimum segment size or the number of levels of the transform, is limited due to independent processing of segments. We show that, with simple modifications in the block boundaries, we can overcome these limitations by, what we call, in-phase lifting implementation of directionlets. In the context of directionlets using in-phase lifting, we identify different possible groups of downsampling matrices that would allow the construction of a multilevel transform without forcing independent processing of segments both with and without any modifications in the segment boundary. Experimental results in image coding show objective and subjective improvements when compared with the directionlets applied independently on each image segment. As an application, using both the in-phase lifting implementation of directionlets and the adaptive directional lifting, we have constructed an adaptive directional wavelet transform, which has shown improved image coding performance over these adaptive directional wavelet transforms.
ISSN: 1057-7149
DOI: 10.1109/TIP.2013.2288912
Schools: School of Electrical and Electronic Engineering 
Rights: © 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. The published version is available at: DOI:
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:EEE Journal Articles

Files in This Item:
File Description SizeFormat 
Directionlets using in-phase lifting for image representation.pdf2.08 MBAdobe PDFThumbnail

Citations 50

Updated on Sep 16, 2023

Web of ScienceTM
Citations 50

Updated on Sep 22, 2023

Page view(s) 10

Updated on Sep 23, 2023

Download(s) 5

Updated on Sep 23, 2023

Google ScholarTM




Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.