Research on Cluster of 7£¯5-Tap Wavelets
Filters and Their Image Compression Performances
Yang Guoan,Zheng Nanning,Liu Yuehu,Liu Zaide,Lan Xuguang,Wu Zongze
(School of Electronics and Information Engineering,Xi'an Jiaotong University,Xi'an
710049,China)
Abstract:A cluster of 7£¯5-tap wavelets filters which include BT 7£¯5 filters of
Brislawn and Treiber was constructed.The construction process of the lifting scheme and
the lifting implement algorithm of 7£¯5-tap wavelets basis were given by the Euclidean
algorithm.The obtained performance of the image compression is the best when the
coefficient ¦Á of the lifting scheme is equal to 0.08 according to the requirement of the
optimization conditions of 7£¯5-tap wavelets basis which is a BT 7£¯5 filter bank
recommended by JPEG2000 standard part II.The coefficients of BT 7£¯5 filters are rational
numbers, compared to CDF 9£¯7 filters with irrational coefficients,and they not only have
advantage of easy computation but also are very suitable for implementation of VLSI
hardware.The experimental results show that the peak signal-to-noise ratio of the
reconstructed image by using BT 7£¯5 filter bank is only 0.1 dB less than CDF 9£¯7
filters, but is higher 1.2 dB than LT 5£¯3(LeGall-Tabatabai) filters within 100¡Ã1
compression ratio. Therefore, the filters constructed are the ideal replacement of LT 5£¯3
and CDF 9£¯7 in JPEG2000 image compression systems.
Keywords:discrete wavelet transform;lifting scheme;wavelet filter; quantization;JPEG2000
JPEG2000