Method of and apparatus for processing image

Abstract

The present invention is directed to a method of and an apparatus for applying predetermined processing to an original image pixel by pixel. A main signal (S) regarding an objective pixel which is a pixel which is to be processed is supplied to an average density value extracting portion (,), a multiplier (,), and a filter computation portion (,). The filter computation portion (,) executes computation based on an image filter which has a larger size than the size of halftone dots, to thereby generates a filtered signal (S′). The average density value extracting portion (,) extracts an average density value (D) in an area which is larger than the size of the halftone dots, and supplies the average density value (D) to a table reference portion (,). The table reference portion (,) identifies a mixing rate (M) for mixing in the main signal (S) and a mixing rate (,−M) for mixing in the filtered signal (S′), in accordance with the average density value (D). The multiplier (,) generates a signal (Sa (=M·S)) while a multiplier (,) generates a signal (Sb (=(1=M)·S′)). Following this, an adder (,) mixes these signals with each other, thereby generating an output signal (S″). As such processing is performed on the entire image, a deterioration in an image quality is suppressed in an excellent manner and moires are removed without deteriorating an edge of the image. Further, a contrast in the vicinity of the objective pixel may be calculated and a mixing rate (M) may be found in accordance with the contrast. In this case as well, it is possible to obtain an image which has an excellent quality.