Block-processing-based image rotation apparatus, system and method

The invention provides a block-processing-based image rotation apparatus, system and method. The method comprises: a DDR reading unit receives an image rotation instruction, coordinate rotation mapping is carried out according to a blocking rule of a rotated image, an original image is divided into a plurality of original sub blocks, access sub blocks are obtained by an access frame, and originalaccess sub block data are read successively from a DDR memory in a first preset order; a sub-block rotation unit carries out pixel rotation calculation on each original sub block according to an imagerotation parameter, corresponding rotation sub block data are generated, and the generated data are sent to an output buffer memory; and a DDR write-back unit reads the output buffer memory, and pixel data of all rotation sub blocks are written back to the DDR memory until writing back of data of all rotation sub blocks is done completely. Therefore, row data inside all sub blocks are continuousin terms of DDR addresses,