Abstract: Disclosed is an image processing apparatus including: a sharpness recovery unit configured to recover sharpness of an input image; a correlation determination unit configured to determine a correlation between a target pixel and peripheral pixels of the input image; a noise removal unit configured to perform smoothing of the target pixel determined as having a correlation with the peripheral pixels in a recovered image output from the sharpness recovery unit; and a switching unit configured to switch between a mode in which the correlation determination unit uses the target pixel and the peripheral pixels of the pre-recovery input image in the correlation determination and a mode in which the correlation determination unit uses the target pixel and the peripheral pixels of the recovered input image in the correlation determination, depending on recovery characteristics used in the determination of the correlation determination unit.

Abstract: The present invention performs inplane uneven density correction that suppresses a number of tone correction properties and has few correction residuals. Accordingly, a correction unit corrects pixel data D based on a plurality of tone correction properties respectively corresponding to a plurality of spot diameters of a light to expose on a surface of a photoreceptor, and to generate a plurality of pieces of correction data D1 and D2. A setting unit sets a ratio Rb based on a spot diameter on the photoreceptor of a pixel corresponding to the pixel data D. A blending unit generates tone correction data Dc by blending the plurality of pieces of correction data D1 and D2 based on the ratio Rb.

Abstract: The image processing apparatus of the present invention includes: an edge determination unit configured to detect an edge pixel to which a white pixel and a black pixel are adjacent in a first direction in an image in which each pixel is represented as a white pixel or a black pixel; a first detection unit configured to detect a number of consecutive pixels up to the edge pixel in the first direction in the image; a second detection unit configured to detect a number of consecutive pixels whose number of consecutive pixels in the first direction is larger than a first threshold in a second direction perpendicular to the first direction in the image; and a type determination unit configured to determine a type of the edge pixel based on detection results by the first detection unit and detection results by the second detection unit.

Abstract: An image that is to be a target for filtering processing is acquired, a plurality of filters having mutually different filter sizes and arrangement spacing for significant coefficients in the filters are applied to the image to perform filtering processing on the image.

Abstract: An image forming apparatus is provided, which is capable of implementing updating of gamma correction information with a high accuracy while avoiding a wasteful output of a patch image even in the case where environmental fluctuations occur. The image forming apparatus corrects a density tone level of image data by using gamma correction information, forms an image based on the corrected image data, and includes an updating unit configured to update the gamma correction information by using a patch image, and the updating unit updates the gamma correction information by using a patch image the output stability of which is high as first updating and further updates the gamma correction information updated by the first updating by using a patch image the sensitivity of which is high as second updating.

Abstract: An image processing apparatus that generates a halftone image by quantizing an input image includes: a holding unit configured to hold a threshold value matrix in which different threshold values are arranged; a pixel position determination unit configured to determine a candidate of a pixel position whose threshold value is to be rewritten based on each pixel value of a plurality of pixels included in a predetermined area for the predetermined area in the input image; and a threshold value determination unit configured to determine a threshold value of the pixel position determined to be the candidate by using at least one threshold value of a plurality of threshold values corresponding to the predetermined area.

Abstract: Sharpness of image data in a low-frequency component, which is deceased by an image forming apparatus, is recovered and the recovered image data is converted into halftone image data. Halftone processing includes calculating edge intensity in a local region, dividing the local region into a first pixel group and a second pixel group based on a pixel value of each pixel, determining a distribution order of dots based on a pixel value of each pixel, a threshold value, and the edge intensity such that dots are likely to be distributed to the first pixel group and dots are unlikely to be distributed to the second pixel group, and determining an output value for each pixel in the local region by distributing dots to some pixels included in the local region as much as a number of dots to be output to the local region while referring to the distribution order.

Abstract: An image processing apparatus divides an input image into a plurality of band area images, stores the respective band area images in a band memory, and performs image processing. The apparatus comprises: a storage unit configured to store filter coefficients having a two-dimensional reference area of M pixels in a first direction and N pixels in a second direction orthogonal to the first direction; and a spatial filter unit configured to apply, to the band area image stored in the band memory, a spatial filter using the filter coefficients. The filter coefficients are set as the filter coefficients so as to refer to pixels for every K pixels in the second direction, and the spatial filter unit sequentially applies the spatial filter to the band area image K times in the second direction.

Abstract: An image processing apparatus according to the present invention includes an acquisition unit configured to acquire an output condition when an image forming apparatus forms an image on a recording medium based on image data, and a processing unit configured to perform image processing on the image data for improving sharpness of the image by using a parameter based on the output condition. The parameter to be referred to by the processing unit represents such a characteristic that the image formed by the image forming apparatus has a luminous characteristic in relation to spatial frequency that remains constant or decreases continuously without causing any inflection point or any discontinuous point in a frequency band from a predetermined frequency to a limit frequency of the image forming apparatus.

Abstract: A color conversion processing apparatus that converts a signal value of an input image into an output value of an actual color material used in an image forming apparatus, and includes: an acquisition unit configured to acquire a printing setting for the input image; and a conversion unit configured to convert the signal value of the input image into the output value of the actual color material in accordance with the acquired printing setting, and the conversion unit performs the conversion while maintaining a relationship between the signal value of the input image and output values of a virtual color material, the number of virtual color materials is smaller than the number of actual color materials and the respective virtual color materials have respective densities corresponding to respective wavelength bands obtained by dividing a wavelength range reproduced by the actual color materials being output into a plurality of wavelength bands, the output values of the plurality of virtual color materials are

Abstract: An image forming apparatus includes a reading unit for sequentially reading, from image data, pieces of pixel data of target pixels along a predetermined direction, a cumulative sum calculation unit for calculating a cumulative sum of gradation values represented by pieces of pixel data of target pixels in a significant image portion read by the reading unit, a determination unit for determining whether the target pixel read by the reading unit is located at a boundary between the significant image portion and a background portion that is a non-significant image portion, and a correction unit for correcting, if the determination unit determines that the target pixel is located at the boundary, a gradation value represented by pixel data of the target pixel by adding a correction amount based on the cumulative sum up to the target pixel calculated by the cumulative sum calculation unit to the gradation value.

Abstract: In order to implement preferred sharpness recovery processing for an image, an image processing apparatus which generates, based on input image data, halftone image data used for an image forming process of forming an image on a print medium. The apparatus converts the input image data into color material amount data used for the image forming process; performs, on the color material amount data, gamma correction to compensate for non-linearity of an input/output density in the image forming process; performs, on the color material amount data after the gamma correction, recovery processing to compensate for sharpness degradation of an image formed by the image forming process; and performs halftone processing on the color material amount data after the recovery processing to generate halftone image data.

Abstract: An image processing apparatus for processing image data by a plurality of pipeline-connected processing modules is provided. The apparatus includes a first pipeline processing unit configured to include a plurality of processing modules including a processing module which processes image data for every first size; and a second pipeline processing unit configured to be branched from the first pipeline processing unit and include a plurality of processing modules including a processing module which processes image data for every second size different from the first size. The second pipeline processing unit includes, at a start, a change unit configured to acquire partial image data of the first size from the first pipeline processing unit and change the partial image data of the first size into partial image data of the second size.

Abstract: In color separation processing by a method that combines a multidimensional LUT and interpolation processing, smooth gradation is implemented by reducing errors accompanying interpolation processing. An image processing apparatus includes a color separation processing unit configured to perform, by interpolation processing using a lookup table having a plurality of dimensions in accordance with signal components of an input image, color separation of an input value that is each pixel value of the input image into an output value corresponding to each of signal components handled by an output device, and each grid point of the lookup table is associated with information representing change characteristics at each portion between adjacent grid points for each dimension of the plurality of dimensions, and in the color separation processing, the interpolation processing is performed based on the information representing the change characteristics.

Abstract: Sharpness of image data in a low-frequency component, which is deceased by an image forming apparatus, is recovered and the recovered image data is converted into halftone image data. Halftone processing includes calculating edge intensity in a local region, dividing the local region into a first pixel group and a second pixel group based on a pixel value of each pixel, determining a distribution order of dots based on a pixel value of each pixel, a threshold value, and the edge intensity such that dots are likely to be distributed to the first pixel group and dots are unlikely to be distributed to the second pixel group, and determining an output value for each pixel in the local region by distributing dots to some pixels included in the local region as much as a number of dots to be output to the local region while referring to the distribution order.

Abstract: Determination information is obtained to determine a degradation characteristic of sharpness of an image formed by an image forming apparatus. One of a plurality of recovery processing parameters used to recover sharpness of an image is selected based on the determination information, and characteristics of the plurality of recovery processing parameters are different from each other. Recovery processing of sharpness is performed on image data using the selected recovery processing parameter. When the degradation characteristics of sharpness are visually and substantially the same, the same recovery processing parameter is selected.

Abstract: Regarding an image forming apparatus for printing an input image and including a print head having a head sensor configured to sense information from the input image printed on a print medium, there is a method of determining a head sensor position parameter in the image forming apparatus. The method includes printing a first swath of the input image on the print medium and determining the head sensor position parameter by performing a sub-method. The sub-method includes capturing, via the head sensor, a target image from the printed first swath, comparing the target image to a reference image for the first swath based upon the input image, and determining the head sensor position parameter based on a relative shift between the target image and the reference image.

Abstract: Screen processing is performed on input image data. A boundary pixel adjacent to a white pixel in the input image data is detected. Output image data based on either the input image data or the screen-processed image data is selectively output for each pixel in accordance with the detection result of the boundary pixel.

Abstract: Multi-value image data is sampled for each predetermined pixel range to generate tone information of the pixel range. The generated tone information is stored in a storage unit. Attribute information representing the attribute of a pixel is generated from the multi-value image data, and the generated attribute information is stored in the storage unit. Halftone processing is performed on the multi-value image data based on the tone information and attribute information stored in the storage unit.

Abstract: An input control apparatus, which accepts input of data from the outside and inputs the data to a bus in a data processing system in which a plurality of communication units are connected by the bus in a ring shape and data processed by processing units are delivered via the bus, controls acceptance of data based on the number of data items which should be output outside, are suspended from output, and remain on the bus.