Title :
Extended lapped transform in image coding
Author :
De Queiroz, Ricardo L. ; Rao, K.R.
Author_Institution :
Dept. of Electr. Eng., Texas Univ., Arlington, TX, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
A modulated lapped transform with extended overlap (ELT) is investigated in image coding with the objective of verifying its potential to replace the discrete cosine transform (DCT) in specific applications. Some of the criteria utilized for the performance comparison are reconstructed image quality (both objective and subjective), reduction of blocking artifacts, robustness against transmission errors, and filtering (for scalability). Also, a fast implementation algorithm for finite-length-signals using symmetric extensions is developed specially for the ELT with overlap factor 2 (ELT-2). This comparison shows that ELT-2 is superior to both DCT and the lapped orthogonal transform (LOT)
Keywords :
digital filters; image coding; image reconstruction; signal flow graphs; transforms; ELT; ELT-2; blocking artifacts; extended lapped transform; filtering; finite-length-signals; image coding; implementation algorithm; modulated lapped transform; overlap factor; performance comparison; reconstructed image quality; robustness; scalability; symmetric extensions; transmission error; Channel bank filters; Cutoff frequency; Discrete cosine transforms; Discrete transforms; Filter bank; Filtering; Finite impulse response filter; Image coding; Phase modulation; Prototypes;
Journal_Title :
Image Processing, IEEE Transactions on
