Flexible compression for bitmap sets

This paper considers the problem of compressing a set of bit maps, exploring the possibility of exploiting the structure between as well as within them to compress the whole bit-table. It describes several particularly simple models of bit occurrence. Two of these are based on detailed assumptions of bit-independence. The third uses regression models. The strategy of separating model construction and compression method continues the well-established practice of basing compression on an explicit model of message generation. Flexible encoding is distinguished from adaptive and static approaches.<<ETX>>