JOURNAL OF COMPUTERS (JCP)
ISSN : 1796-203X
Volume : 1    Issue : 4    Date : July 2006

Backward Coding of Wavelet Trees with Fine-grained Bitrate Control
Jiangling Guo, Sunanda Mitra, Brain Nutter and Tanja Karp
Page(s): 1-7
Full Text:
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Abstract
Backward Coding of Wavelet Trees (BCWT) is an extremely fast wavelet-tree-based image coding
algorithm. Utilizing a unique backward coding algorithm, BCWT also provides a rich set of features
such as resolution- scalability, extremely low memory usage, and extremely low complexity.
However, BCWT in its original form inherits one drawback also existing in most non-bitplane
codecs, namely coarse bitrate control. In this paper, two solutions for improving the bitrate
controllability of BCWT are presented. The first solution is based on dual minimum quantization
levels, allowing BCWT to achieve fine-grained bitrates with quality-index as a controlling parameter;
the second solution is based on both dual minimum quantization levels and a coding histogram,
providing the ability to use target bitrate as the controlling parameter with only a small speed penalty.

Index Terms
image coding, wavelet tree, backward coding, bitrate control, quality index, coding histogram.