Image processing apparatus and image processing method

Claim 1

An image processing apparatus comprising: a characteristic signal calculation section that calculates at least one characteristic amount of an input image signal to produce a first characteristic signal; a conversion process section that executes a conversion process for decreasing a resolution and the number of bits of the first characteristic signal produced by the characteristic signal calculation section to convert the first characteristic signal into a second characteristic signal having a characteristic amount smaller than that of the first characteristic signal; a storing section that stores the second characteristic signal that is obtained by conversion by the conversion process section; a processor that reads out the second characteristic signal stored in the storing section, and executes an arithmetic operation for only a macro-scoped correction process with software or an arithmetic operation for both the macro-scoped correction process and a macro-discrimination process with the software; a synthesizing process section that outputs a discrimination signal obtained by synthesizing an arithmetic result of the processor and the first characteristic signal produced by the characteristic signal calculation section; and an image processing section that executes a color conversion process, a frequency filtering process and a tone process for the image signal in accordance with the discrimination signal output from the synthesizing process section, wherein in the macro-scoped process, a pixel value is corrected by one of a smearing process in which pixel values of pixels interposed between two pixels which both have a value “1”, and which are separated from each other by a distance of a predetermined value or less are changed to “1”, and a majority process in which the number of pixels having pixel value “1”, which are included in pixels close to a pixel of interest, is counted, and when the counted number is greater than a predetermined value, an output value is determined as “1”, and when the counted number is smaller than the predetermined value, the output value is determined as “0”, and wherein in the macro-discrimination process, a connected region is extracted with respect to a white background region, a halftone region, a character region and a halftone-dot region, and the extracted connected region is determined as one of a background graphic, a halftone-dot background graphic, a halftone-dot photo and a continuous photo region.