Abstract: This invention provides methods for pattern discovery, pattern matching and data compression in multidimensional numerical datasets. The invention can usefully be applied in any domain in which information represented in the form of multidimensional datasets needs to be retrieved, compared, analysed or compressed. Such domains include 2D images, audio and video data, biomolecular data, seismic, meteorological and financial data. There already exist methods for pattern discovery, pattern matching and data compression but these methods have been designed for processing data represented as strings and there are many domains in which data cannot be appropriately represented using strings. In such domains, existing data-processing methods are not effective. In many of the domains in which strings cannot be effectively used to represent information (e.g., audio and video data), the data can be represented using multidimensional numerical datasets. The present invention provides methods for processing such datasets.