Abstract: Image area data in an uncompressed data field is digitized as binary data and subsectioned into data bit blocks. The subsections are compressed whereby each subsection is represented in terms of its predominant data values plus non-redundant data occurrences. Several predominant values are chosen from the subsection of interest. Each of the predominant values is assigned a bit code and data values from the subsection that are identical to a predominant value are assigned a code corresponding to the predominant value. Uncoded remaining data values and the coded data values are stored in a variable length record so that each data location within the record spatially corresponds to the location of the original data in the uncompressed data field.