An image processing apparatus includes a reading unit configured to read an image of a document and generate image data, a first binarization unit configured to generate binary image data by performing halftone processing on the image data generated by the reading unit, a smoothing unit configured to perform smoothing processing on a character region of the binary image data, a second binarization unit configured to perform binarization processing on the character region having been subjected to the smoothing processing by the smoothing unit, and a character recognition unit configured to perform character recognition processing on the character region having been subjected to the binarization processing by the second binarization unit.

A copy-evident document and a method of printing a copy-evident document wherein a void pantograph is created including a first set of halftone elements and a second set of halftone elements different in modulation from the first set of halftone elements. An overlay including a white image with a plurality of halftone hole locations is preferably formed, wherein the halftone elements of the void pantograph are converted to the plurality of halftone hole locations. The overlay is then preferably merged with a background image, such that portions of the background image are visible at the halftone hole locations of the overlay when printed. The merged image is then printed on print media, wherein the portions of the background image that are printed are printed at locations where the holes locations are present in the overlay creating a copy-evident feature.

A frequency adaptive descreening method includes obtaining a scan image of an original document, dividing a region of the scan image by analyzing frequency characteristics of the obtained scan image, estimating a resolution with respect to each of regions resulting from dividing the region according to the analyzed frequency characteristics, and adaptively performing filtering on the regions resulting from dividing the region by using the estimated resolution.

Processing a dithered image comprising a grid of pixels including defining an array of pixels corresponding to a sub-region of the image; performing edge detection along the rows and the columns of the array; counting the number of edges detected along the rows of the array to determine the number of horizontal edges in the array; counting the number of edges detected along the columns of the array to determine the number of vertical edges in the array; identifying whether the sub-region is dithered based on the number of horizontal and vertical edges in the array; and selectively processing the corresponding sub-region of the image based on whether or not the sub-region is identified to be dithered. The identification step may also be based on the lengths of segments of similar pixels in the lines of the array.

A copy-evident document and a method of printing a copy-evident document wherein a void pantograph is created including a first set of halftone elements and a second set of halftone elements different in modulation from the first set of halftone elements. An overlay including a white image with a plurality of halftone hole locations is preferably formed, wherein the halftone elements of the void pantograph are converted to the plurality of halftone hole locations. The overlay is then preferably merged with a background image, such that portions of the background image are visible at the halftone hole locations of the overlay when printed. The merged image is then printed on print media, wherein the portions of the background image that are printed are printed at locations where the holes locations are present in the overlay creating a copy-evident feature.

Systems and methods for replacing cells of an image based on some pre-determined metric are described herein. For example, systems and methods described herein may improve the functioning of a standard imaging system. For example, the systems and methods described herein may be used to post-process existing images in an imaging system based on one or more pre-determined metrics and improve the halftone images according to those pre-determined metrics.