A data processing system comprises processing circuitry arranged to generate data to form an output array of data, processing circuitry arranged to store the generated data in an output buffer 15 by writing compressed blocks of data representing particular regions of the output array of data to the output buffer, processing circuitry 14 arranged to read a compressed block of data representing a particular region of the array of data from the output buffer, processing circuitry 16 arranged to acquire meta-data from the compressed block of data, and processing circuitry 21 arranged to process the block of data. The acquired meta-data is used to affect the processing of the block of data.