H. S. Malvar
We introduce a new image compression algorithm that allows progressive image reconstruction – both in resolution and in fidelity, with a fully embedded bit-stream. The algorithm is based on bit-plane entropy coding of reordered trans-form coefficients, similar to the progressive wavelet codec (PWC) previously introduced. Unlike PWC, however, our new progressive transform coder (PTC) does not use wavelets; it performs the space-frequency decomposition step via a new lapped biorthogonal transform (LBT). PTC achieves a rate vs. distortion performance that is comparable (within 2%) to that of the state-of-the-art SPIHT (set partitioning in hierarchical trees) codec. However, thanks to the use of the LBT, the space-frequency decomposition step in PTC reduces the number of multiplications per pixel by a factor of 2.7, and the number of ad-ditions by about 15%, when compared to the fastest possible implementation of the “9/7” wavelet transform via lifting. Furthermore, since most of the computation in the LBT is in fact performed by a DCT, our PTC codec can make full use of fast software and hardware modules for 1-D and 2-D DCTs.
|Published in||Data Compression Conference|
|Publisher||Institute of Electrical and Electronics Engineers, Inc.|
© 2007 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.