Title :
Modified EZW coding for the M-band wavelet transform and its application to image compression
Author :
Bhokare, G.D. ; Karthik, R.J.
Author_Institution :
Electr. Eng., IIT Bombay
Abstract :
This paper describes the extension of the embedded zero wavelet tree coding technique (J.M. Shapiro, 1993) to the M-band wavelet transform. Through this scheme, we improve the efficiency of the embedded zero wavelet tree coding, that finds extensive application as a variable bit-rate coder. To prove the efficacy, we compare the compression ratio and the PSNR obtained by a traditional 2-band wavelet based coder, with those obtained with the M-band wavelet based EZW coder. One additional point discussed in this paper, is the performance of a traditional 2-level quantization in EZW against an M-adaptive coder. We see the advantages and disadvantages in going in for an M-adaptive coder and conclude based on the PSNR and compression ratio obtained at various bit-rates. The variable bit-rate is emulated as multiple scans. Hence graphs plot the compression ratio or the PSNR against the number of scans. An important inference drawn from this paper is that, M-band wavelet transform with M=Odd, exhibits special properties, as a result of which the EZW scheme performs much more efficiently with them
Keywords :
adaptive codes; data compression; image coding; transform coding; tree codes; wavelet transforms; EZW coding; M-adaptive coder; M-band wavelet transform; PSNR; compression ratio; embedded zero wavelet tree coding technique; image compression; quantization; Band pass filters; Discrete cosine transforms; Discrete wavelet transforms; Filter bank; Image coding; Low pass filters; PSNR; Quantization; Signal resolution; Wavelet transforms;
Conference_Titel :
Statistical Signal Processing, 2005 IEEE/SP 13th Workshop on
Conference_Location :
Novosibirsk
Print_ISBN :
0-7803-9403-8
DOI :
10.1109/SSP.2005.1628718