Patent ID: 7180636

Claim:
An image processor, comprising: a region discrimination unit which determines whether each pixel of image data is a pixel in a character edge region or a pixel in a continuous tone region; a first tone reproduction unit which performs tone reproduction processing with an emphasis on resolution of the image data; a second tone reproduction unit which performs tone reproduction processing with an emphasis on gradation on the image data; and an image output unit which produces an output after performing the processing by the first tone reproduction unit or the processing by the second tone reproduction unit based on a result of the determination by the region discrimination unit, wherein the processing by the second tone reproduction unit includes at least smoothing on the image data and screening on the image data having undergone smoothing, the smoothing is performed to reduce moiré generated by screening, and when a region discrimination size in the region discrimination unit is n×n pixels and a size of a filter for the smoothing performed by the second tone reproduction unit is m×m pixels, a relationship n≧m holds.