Abstract: Provided is an image reading apparatus, including an update unit that updates a color correction coefficient of an image read signal of an image read by a reading unit using a color reference surface provided with an achromatic color reference surface and a chromatic color reference surface, a first detection unit that detects existence of dust based on read information of the achromatic color reference surface, a second detection unit that detects existence of the dust based on the read information of the chromatic color reference surface, and a third detection unit that detects a type of an optical component onto which the dust is attached according to a detection result of the first detection unit and the second detection unit.

Abstract: A printing system includes the following elements. An addition unit creates additional image data having a specific attribute and adds it to original image data, thereby creating document image data. An image forming unit forms a document image including an original image and an additional image on a recording medium on the basis of the document image data. An image reader reads the document image, thereby creating read image data. A difference image creator creates difference image data by calculating a difference between the original image data and the read image data. A canceling unit corrects, on the basis of the specific attribute, the difference image data by canceling a difference generated due to the addition of the additional image data, thereby creating corrected difference image data. An inspection unit performs inspection to find a defect of the original image on the basis of the corrected difference image data.

Abstract: An image reading device includes a light source, a light receiving unit, a generation unit, a white reference member, a color reference member, and a processing unit. The light source emits light to a recording medium on which an image is formed. The light receiving unit receives light reflected by the recording medium. The generation unit generates a light intensity value from the light received by the light receiving unit. The white reference member is used for color calibration for a white balance. The color reference member is used for color calibration to calibrate a predetermined color. The processing unit derives a correlation formula representing variation in characteristics of the white reference member, based on a light intensity value generated when light is emitted to the color reference member from the light source.

Abstract: A printing system includes the following elements. An image forming unit forms an image. An image reader reads an image. A first color converter creates second image data. A second color converter creates fourth image data. A determining unit determines whether a pixel value of each of pixels in the first image data or the second image data is located inside or outside an input color gamut that is readable by the image reader. A correction unit corrects pixels located at the same position as a pixel having a pixel value located outside the input color gamut. An inspection unit performs inspection to find a defect of an image. The correction unit performs correction on the pixels located at the same position as a pixel having a pixel value located outside the input color gamut so that the inspection unit does not detect a difference between the corrected pixels.

Abstract: A printing system includes following components. An image forming section forms an image on a recording medium using first image data. A first image creation section creates the first image data by performing first image processing including correction of a characteristic unique to the image forming section and first processing, on original image data. The second image creation section creates second image data by performing second image processing including the first processing but not including the correction of a characteristic unique to the image forming section, on the original image data. The image reading section reads the image on the recording medium to obtain read image data. The detection section detects a defect in the image on the recording medium, by comparing on a pixel-by-pixel basis the read image data or comparison image data obtained by processing the read image data with the second image data.

Abstract: An image scanner includes: a light source that irradiates, with light, a recording medium on which an image is formed; a light receiving portion that receives light reflected by the recording medium; a generating portion that generates a light amount value from the light received by the light receiving portion; a measuring portion in which plural reflecting surfaces are disposed, the reflecting surfaces respectively having predetermined colors different from each other; and a processing portion that derives a correlation formula from a light amount value generated at predetermined reference time and from a light amount value generated when the reflecting surfaces in the measuring portion are irradiated with the light from the light source, the correlation formula expressing a time-varying change in the light source.

Abstract: An image reader includes a light source that irradiates light to a recording material on which an image is formed, a generation section that receives light reflected from the recording material and generates image information from the received light, and a processing section that extracts information corresponding to a window region of the recording material set in advance, as correction information, from the image information generated by the generation section when light from the light source is irradiated to the recording material on which the image is formed.

Abstract: A printing system includes following components. An image forming section forms an image on a recording medium using first image data. A first image creation section creates the first image data by performing first image processing including correction of a characteristic unique to the image forming section and first processing, on original image data. The second image creation section creates second image data by performing second image processing including the first processing but not including the correction of a characteristic unique to the image forming section, on the original image data. The image reading section reads the image on the recording medium to obtain read image data. The detection section detects a defect in the image on the recording medium, by comparing on a pixel-by-pixel basis the read image data or comparison image data obtained by processing the read image data with the second image data.

Abstract: A printing system includes the following elements. An addition unit creates additional image data having a specific attribute and adds it to original image data, thereby creating document image data. An image forming unit forms a document image including an original image and an additional image on a recording medium on the basis of the document image data. An image reader reads the document image, thereby creating read image data. A difference image creator creates difference image data by calculating a difference between the original image data and the read image data. A canceling unit corrects, on the basis of the specific attribute, the difference image data by canceling a difference generated due to the addition of the additional image data, thereby creating corrected difference image data. An inspection unit performs inspection to find a defect of the original image on the basis of the corrected difference image data.

Abstract: A printing system includes the following elements. An image forming unit forms an image. An image reader reads an image. A first color converter creates second image data. A second color converter creates fourth image data. A determining unit determines whether a pixel value of each of pixels in the first image data or the second image data is located inside or outside an input color gamut that is readable by the image reader. A correction unit corrects pixels located at the same position as a pixel having a pixel value located outside the input color gamut. An inspection unit performs inspection to find a defect of an image. The correction unit performs correction on the pixels located at the same position as a pixel having a pixel value located outside the input color gamut so that the inspection unit does not detect a difference between the corrected pixels.

Abstract: A printing system includes following components. A deciding unit decides, by using setting data and output image data including pieces of original image data corresponding to plural pages, a printing order in which the plural pages are to be printed. A printing unit respectively prints images of the plural pages on recording media by using the output image data, in accordance with the printing order. A reading unit reads, in accordance with the printing order, the images of the plural pages having been printed on the recording media to obtain pieces of read image data corresponding to the plural pages. An identifying unit identifies pieces of reference image data corresponding to the plural pages of the output image data, in accordance with the printing order. A verification unit verifies, for each page, the piece of read image data of the page against the corresponding piece of reference image data.

Abstract: The reading apparatus is provided with: an optical image forming unit that forms an optical image on a recording medium by irradiating, with light, the recording medium on which an image is formed and which is transported in a slow scan direction; a reading unit that reads a position in a fast scan direction of the image formed on the recording medium transported in the slow scan direction and a position in a fast scan direction of the optical image, by using a minification optical system; and a registration correction unit that corrects a registration error in the fast scan direction of the image read by the reading unit, by using the position in the fast scan direction of the optical image read by the reading unit.

Abstract: An image reading device includes a light source, a light receiving unit, a generation unit, a white reference member, a color reference member, and a processing unit. The light source emits light to a recording medium on which an image is formed. The light receiving unit receives light reflected by the recording medium. The generation unit generates a light intensity value from the light received by the light receiving unit. The white reference member is used for color calibration for a white balance. The color reference member is used for color calibration to calibrate a predetermined color. The processing unit derives a correlation formula representing variation in characteristics of the white reference member, based on a light intensity value generated when light is emitted to the color reference member from the light source.

Abstract: An image reader includes a light source that irradiates light to a recording material on which an image is formed, a generation section that receives light reflected from the recording material and generates image information from the received light, and a processing section that extracts information corresponding to a window region of the recording material set in advance, as correction information, from the image information generated by the generation section when light from the light source is irradiated to the recording material on which the image is formed.

Abstract: An image scanner includes: a light source that irradiates, with light, a recording medium on which an image is formed; a light receiving portion that receives light reflected by the recording medium; a generating portion that generates a light amount value from the light received by the light receiving portion; a measuring portion in which plural reflecting surfaces are disposed, the reflecting surfaces respectively having predetermined colors different from each other; and a processing portion that derives a correlation formula from a light amount value generated at predetermined reference time and from a light amount value generated when the reflecting surfaces in the measuring portion are irradiated with the light from the light source, the correlation formula expressing a time-varying change in the light source.

Abstract: A color correction data acquiring system includes: an analysis unit that analyzes a data uniform part in an input image; and an area setting unit that sets a patch data acquiring area based on an analysis result of the analysis unit. The color correction data acquiring system acquires color correction data based on a patch data in the patch data acquiring area of the input image and a patch data in the patch data acquiring area of a read image.

Abstract: A split image generation portion generates split images. A split projected waveform generation portion generates split projected waveforms from the split images respectively. A projected waveform synthesizer portion generates projected waveforms by combining the split projected waveforms. A feature volume extraction portion extracts feature volumes from the generated projected waveforms. A feature volume correlation portion correlates feature volume data of a target image with feature volume data of a reference image. A correction value calculation portion calculates correction values in accordance with geometrical distortion between the reference image and the target image on the basis of a result of the correlation and generates an n-dimensional lookup table. An image collation portion collates the target image with the reference image in consideration of the geometrical distortion by using the lookup table.

Abstract: The reading apparatus is provided with: an optical image forming unit that forms an optical image on a recording medium by irradiating, with light, the recording medium on which an image is formed and which is transported in a slow scan direction; a reading unit that reads a position in a fast scan direction of the image formed on the recording medium transported in the slow scan direction and a position in a fast scan direction of the optical image, by using a minification optical system; and a registration correction unit that corrects a registration error in the fast scan direction of the image read by the reading unit, by using the position in the fast scan direction of the optical image read by the reading unit.

Abstract: An image collating apparatus comprises a device for setting a plurality of predetermined paths in a reference image and a check image and accumulating pixel values in the paths of both images with respect to the plurality of paths to obtain a projected waveform or histogram of the reference and the check image; a device for generating information of a characteristic value as reference characteristic value information based on the projected waveform or histogram of the reference image; a device for generating the information of the characteristic value as check characteristic value information based on the projected waveform or histogram of the check image; and a device for collating the reference image with the check image based on the reference characteristic value information and check characteristic value information.

Abstract: A color correction data acquiring system includes: an analysis unit that analyzes a data uniform part in an input image; and an area setting unit that sets a patch data acquiring area based on an analysis result of the analysis unit. The color correction data acquiring system acquires color correction data based on a patch data in the patch data acquiring area of the input image and a patch data in the patch data acquiring area of a read image.