Representing source data with predefined data patterns, or identifying predefined data patterns in source data, where each data pattern includes a unique combination of pattern elements, without comparing every pattern element of each data pattern to the source data. A hierarchical structure of relationships between the data patterns is predetermined in an initialization stage by comparing the data patterns to identify identical pattern elements among groups of the data patterns. Selected node elements in a resulting relationship tree are compared to the source data to determined deviations. The deviations are propagated and accumulated throughout the relationship structure of the tree, and data patterns having the minimum deviation are selected to represent corresponding source data cells. A graphics pipeline preferably is used to determine the deviations and select data patterns in real time.