Dual-DCT-Lifting-Based Lapped Transform with Improved Reversible Symmetric Extension

Taizo SUZUKI  Masaaki IKEHARA  

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E100-A   No.5   pp.1109-1118
Publication Date: 2017/05/01
Online ISSN: 1745-1337
Type of Manuscript: PAPER
Category: Digital Signal Processing
Keyword: 
discrete cosine transform,  lapped transform,  lifting structure,  lossy-to-lossless image coding,  reversible symmetric extension,  

Full Text: PDF(1.3MB)
>>Buy this Article


Summary: 
We present a lifting-based lapped transform (L-LT) and a reversible symmetric extension (RSE) in the boundary processing for more effective lossy-to-lossless image coding of data with various qualities from only one piece of lossless compressed data. The proposed dual-DCT-lifting-based LT (D2L-LT) parallel processes two identical LTs and consists of 1-D and 2-D DCT-liftings which allow the direct use of a DCT matrix in each lifting coefficient. Since the DCT-lifting can utilize any existing DCT software or hardware, it has great potential for elegant implementations that are dependent on the architecture and DCT algorithm used. In addition, we present an improved RSE (IRSE) that works by recalculating the boundary processing and solves the boundary problem that the DCT-lifting-based L-LT (DL-LT) has. We show that D2L-LT with IRSE mostly outperforms conventional L-LTs in lossy-to-lossless image coding.