SSRLE: Substitution and Segment-Run Length Encoding for Binary Data in XML

Abstract

With the increasing use of XML as an information exchange format, there is an increasing need to embed graphics and binary data files within XML documents. This paper describes a technique called substitution and segment-run length encoding (SSRLE) for including binary data in XML documents. Traditional encodings like base 64 and ASCII 85 use a subset of the available printable characters and add considerable space overhead. Alternatives such as packaging and binary XML encodings do not preserve the portability of XML documents. SSRLE uses additional printable characters for substitutions and segment-run lengths to provide savings in terms of the space overhead, with a worst case overhead equal to that of base 64. Our experiments show that SSRLE provides significant space savings for a number of types of different files