---------------------------------------------------------------------- --- EPIC (Efficient Pyramid Image Coder) --- --- Designed by Eero P. Simoncelli and Edward H. Adelson --- --- Written by Eero P. Simoncelli --- --- Developed at the Vision Science Group, The Media Laboratory --- --- Copyright 1989, 1990, 1991, 1992, Massachusetts Institute of --- --- Technology. Copyright 1993, 1994, 1995 University of --- --- Pennsylvania. All rights reserved. --- ---------------------------------------------------------------------- Permission to use, copy, or modify this software and its documentation for educational and research purposes only and without fee is hereby granted, provided that this copyright notice and the original authors' names appear on all copies and supporting documentation. For any other uses of this software, in original or modified form, including but not limited to distribution in whole or in part, specific prior permission must be obtained from M.I.T. and the authors. These programs shall not be used, rewritten, or adapted as the basis of a commercial software or hardware product without first obtaining appropriate licenses from M.I.T. M.I.T. makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty. ---------------------------------------------------------------------- EPIC (Efficient Pyramid Image Coder) is an experimental image data compression utility written in the C programming language. The compression algorithms are based on a biorthogonal critically-sampled dyadic wavelet decomposition and a combined run-length/Huffman entropy coder. The filters have been designed to allow extremely fast decoding on conventional (ie, non-floating point) hardware, at the expense of slower encoding and a slight degradation in compression quality (as compared to a good orthogonal wavelet decomposition). We are making this code available to interested researchers who wish to experiment with a subband pyramid coder. We have attempted to optimize the speed of pyramid reconstruction, but the code has not been otherwise optimized, either for speed or compression quality. In particular, the pyramid construction process is unnecessarily slow, quantization binsizes are chosen to be the same for each subband, and we have used a very simple scalar entropy coding scheme to compress the quantized subbands. Although this coding technique provides good coding performance, a more sophisticated coding scheme (e.g., utilizing an arithmetic coder, or a vector quantizer) combined with this pyramid decomposition could result in substantial coding gains. EPIC is currently limited to 8-bit monochrome images, and does not explicitly provide a progressive transmission capability. EPIC is available via anonymous ftp from ftp.cis.upenn.edu (IP number 158.130.12.3) in the file pub/eero/epic.tar.Z. This is a unix-compressed tarfile: don't forget to put ftp into BINARY mode. EPIC is also available via the World Wide Web at the following URL: http://www.cis.upenn.edu/~eero/epic.html See the file USAGE for detailed instructions on installing/using EPIC. See the file ChangeLog for recent changes to EPIC. If you acquire a copy of EPIC and make use of it in your research, please consider referencing some of the publications described below. Comments, suggestions, or questions should be sent to: Prof. Eero P. Simoncelli GRASP Laboratory, Rm 335C 3401 Walnut Street Philadelphia, PA 19104-6228 WWW: http://www.cns.nyu.edu/~eero/index.html ------------------------------------------------------------------------- REFERENCES: Edward H Adelson, Eero P Simoncelli, and Rajesh Hingorani. Orthogonal pyramid transforms for image coding. In Proceedings of SPIE, October 1987, Volume 845. [ftp://ftp.cis.upenn.edu/pub/eero/adelson87.ps.gz] Eero P. Simoncelli. Orthogonal Sub-band Image Transforms. Master's Thesis, EECS Department, Massachusetts Institute of Technology. May, 1988. Also available as MIT Media Laboratory Vision and Modeling Technical Report #100. Edward H Adelson and Eero P Simoncelli, "Truncated Subband Coding of Images". U.S. Patent Number 4,917,812. 1989. Eero P Simoncelli and Edward H Adelson. Subband Transforms. Chapter 4 of "Subband Image Coding", ed. John Woods. Kluwer Academic Publishers, 1990. [ftp://ftp.cis.upenn.edu/pub/eero/simoncelli90.ps.Z] Edward H Adelson, Eero P Simoncelli. Subband Image Coding with Three-tap Pyramids. Picture Coding Symposium, 1990. Cambridge, MA. [ftp://ftp.cis.upenn.edu/pub/eero/EPIC.ps.Z]