IMAGE PROCESSING APPARATUS AND METHOD THEREFOR

PROBLEM TO BE SOLVED: To appropriately diffuse an error between regions when performing error diffusion processing on an image divided into plural regions.SOLUTION: When a target pixel exists at a pixel position where reference of an error buffer 309 is necessary, an error buffer control unit 308 acquires a quantization error to be referenced generated in error diffusion processing in a region already subjected to error diffusion processing from the error buffer 309. A multiplication unit 306 acquires a quantization error generated in error diffusion processing on the neighborhood of the target pixel in a region including the target pixel from an error memory 305. The multiplication unit 306 and an integration unit 307 calculate a diffusion error from the quantization error according to an error diffusion matrix. An error addition unit 300 adds a value of the target pixel and the diffusion error, and a quantization unit 301 quantizes the addition value into a quantization value of the target pixel. A quantization error calculation unit 302 calculates the difference between the quantization value of the target pixel and the addition value as a quantization error and stores the quantization error in the error memory 305. When the target pixel exists at a pixel position where write in the error buffer 309 is necessary, the error buffer control unit 308 stores the quantization error of the target pixel in the error buffer 309.