Abstract: A video image processing system comprises an input cache store for temporarily storing input video data, compressors for compressing image data from the input store and an output store comprising multiple storage areas of known fixed size for storing respective files of compressed data from the compressors. The compressors are arranged to compress each image of the input video data to a given initial degree to produce respective data files. A processor compares the number of bytes in each data file with the known size of one storage area in the output store to determine whether the data file will occupy a predetermined proportion of said storage area. In the event that the data file will not occupy said predetermined portion of said storage area, the processor causes one of the compressors to effect one or more repeat compressions to a different degree in order to produce a data file of a size which will occupy said predetermined proportion of said storage.