FULLY SCALABLE IMAGE AND VIDEO CODEC BASED ON 2 & 3 DIMENSIONAL SUBBAND TRANSFORMATION AND PROGRESSIVE CODING OF SUBBAND COEFFICIENTS by David S. Taubman University of California, Berkeley ----------------------- I am pleased to announce the release of very flexible compression and decompression software. Unlike conventional compression standards, this software performs fully scalable compression of both video and images. This means that subsets may be extracted from the compressed bit stream so as to satisfy virtually any constraint on bit rate and a wide range of compatible display frame resolutions and frame rates. That is, the compressed bit stream is generated once only, after which scaling may occur to meet demands imposed by storage, distribution and display systems. Software is located at: robotics.eecs.berkeley.edu in /pub/multimedia/scalable.tar.Z Correspondence should be directed to: scalable@robotics.eecs.berkeley.edu The `scalable.tar.Z' file contains: software and documentation; a copy of a journal paper, discussing the theoretical aspects of the algorithm together with experimental performance results; and examples. Software is driven by a general configuration language, enabling numerous compression algorithms to be generated within the scalable context. Decompression with compatible, but not identical configurations enables frame resolution and frame rate scalability. Although frame rate and frame resolution scalability are primarily of value for compatible decompression, bit rate scalability is of value throughout the path from compression, possibly to storage, through distribution and eventually to decompression. Bit rate scalability is currently only implemented within the compression and decompression software, so that bit rate constraints may be imposed immediately after compression and/or immediately before decompression. With with some effort, the bit rate scaling algorithm could be moved to any one or more points in the distribution path at which rate scaling is desirable. The decompression software comes with a separate viewing console with VCR-like controls for video playback on high end workstations. Initial investigations suggest the following: [Still] For colour/monochrome still image compression, the compression efficiency ranks amongst the best reported anywhere in the literature for scalable and non-scalable codecs over a very wide range of bit rates. Certainly very much better than JPEG. [Video] For video compression of progressively scanned video sequences, the compression efficiency is comparable to that of the non-scalable MPEG-1 standard. Generally, performance is significantly better than MPEG when camera motion conforms to a pan model (i.e. still, jitter, and true pan), regardless of the amount of foreground motion. On the other hand, performance can be significantly worse (2-3 dB) than MPEG when camera motion is zoom or translation and when there is little or no complex foreground motion. It is important to appreciate, however, that the primary feature of this suite of compression algorithms is scalability. Computational complexity appears to be perhaps twice that of MPEG, however the algorithm is inherently amenable to highly parallel hardware or software implementation. Feel free to experiment with the software and send us feedback regarding your experiences and/or application ideas. David Taubman (June 30, 1994)