Low power and low memory single-pass multi-dimensional digital filtering

Abstract

Disclosed are new approaches to Multi-dimensional filtering with a reduced number of memory reads and writes. In one embodiment, a filter includes first and second coefficients. A block of a data having width and height each equal to the number of one of the first or second coefficients is read from a memory device. Arrays of values from the block are filtering using the first filter coefficients and the results filtered using the second coefficients. The final result may be optionally blended with another data value and written to a memory device. Registers store results of filtering with the first coefficients. The block of data may be read from a location including a source coordinate. The final result of filtering may be written to a destination coordinate obtained by rotating and/or mirroring the source coordinate. The orientation of arrays filtered using the first coefficients varies according to a rotation mode.