An apparatus and method for compressing binarized images (90) comprising receiving a binarized image (70) and generating a first sequence of first code symbols (80) representing the binarized image wherein at least one row of the image is represented in run-length encoded format and encoding a portion of the first sequence of code symbols using a preliminary encoding scheme, thereby to provide a first portion of a second sequence of code symbols, and, while encoding, accumulating the frequency of at least some of the first code symbols thus far encoded (100) and generating an additional portion of the second sequence using a modified version of the code scheme such that at least one subsequent code symbol in the first sequence with a large accumulated frequency is encoded more compactly in the second portion than at least one subsequent code symbol in the first sequence with a small accumulated frequency.