IMAGE COMPOSITION DEVICE AND IMAGE COMPOSITION METHOD

摘要

An image combining apparatus and an image combining method for minimizing the- occupation of busses and for combining images at high performance and low power consumption. An image data memory (100) generates update history information that indicates which image data is updated. A combiner (110) reads only updated image data based on the update history information and generates combined image updating data. A display control information generator (120) generates display control information containing transparent data and non-transparent data, respectively indicating the transparent portion and the non-transparent portion of the combined image updating data. A writer (150) writes the combined image updating data into a combined image memory (160). Then, the writer (150) writes the combined image updating data over a previously generated combined image, letting the portion corresponding to the transparent data in the display control information be transparent, and not letting the portion corresponding to the non-transparent data pass. <IMAGE>