Data compression

Abstract

A data compression apparatus comprises a source detection arrangement for detecting whether or not the input data is source data that has not undergone a previous compression/decompression cycle; a data quantity generator, responsive to the source detection arrangement, for setting a desired data output quantity for the compressed data, the desired data quantity having a first value for source input data and a second, higher, value for non-source input data; a target allocator for allocating a target data quantity to respective subsets of the input data in dependence upon the desired output data quantity, the target data quantities together providing a desired output data quantity; and a data compression arrangement for compressing each subset of the input data in accordance with its respective target data quantity.

Dependencies are inferred from the claim text.