Abstract

A method and apparatus for compression of data using a technique for quantization and encoding referred to as Mapping through Interval Refinement (MIR). The method uses the size of the original data set together with a target compression ratio to determine the size of a compressed representative of the original data. The data elements after de-correlation are effectively sorted in decreasing order of significance and then written to an output data set using an efficient encoding method which incrementally refines the precision of elements already output. The output process continues until the target compressed file size is reached. Decompression of the compressed data is accomplished by reading in the sorted elements and restoring them to their locations in the data set, and to the precisions saved in the compression process. The method and apparatus employing it are applicable to time series data as well as multi-dimensional data such as color contone images used in the graphic arts electronic pre-press field.