A reading device includes a first light source, a second light source, a first reading unit, a second reading unit, a comparison unit, and a correction unit. The first source irradiates an object to be read, with first light having a first transmittance to the object. The second source irradiates the object with second light having a second transmittance to the object. The first reading unit reads the first light from the object to output first image data. The second reading unit reads the second light from the object to output second image data. The comparison unit compares a data difference between the first and second image data. In a case where the data difference is equal to or larger than a threshold, the correction unit corrects data of an image area having the data difference equal to or larger than the threshold in the first or second image data.

An image processing apparatus comprises a reading unit configured to read an image of an original; a correction unit configured to correct, based on variance values acquired for a pixel, the pixel in a region where a show-through has occurred, in the image read by the reading unit; a designation unit configured to designate a chromatic color; and a conversion unit configured to convert a pixel included in an image including the pixel corrected by the correction unit into one of a chromatic color and an achromatic color designated by the designation unit.

An image forming apparatus includes a printer configured to print on a print medium, and a reading unit configured to acquire color information of an image printed on the print medium. In printing on both sides being a first side and a second side of the print medium opposite the first side, upon a determination that a predetermined condition is met, the reading unit is configured to acquire the color information of the image printed on the first side of the print medium, after printing on the first side of the print medium is provided and before printing on the second side of the print medium is provided.

An image reading device includes a first scanner, a second scanner, and circuitry. The first scanner is configured to read a first side of a recording medium. The second scanner is configured to read a second side of the recording medium. The circuitry is configured to generate a first correction value to correct misalignment between the first side and the second side. The circuitry is configured to input a second correction value. The circuitry is configured to correct an image based on the first correction value and the second correction value.

Show-through is suitably removed while an image, such as a tag or highlighter, on a first surface is prevented from being removed. A luminance value of a pixel of a target region is increased based on a first correction amount in a case where the pixel is not a pixel of a halftone dot region and a value specified based on a saturation of the pixel of the target region is less than a predetermined value, or a luminance value of the pixel is increased based on a second correction amount less than the first correction amount in a case where the pixel is not a pixel of the halftone dot region and the value specified based on the saturation of the pixel of the target region is greater than or equal to the predetermined value.

The image processing apparatus obtains a degree of variation in signal values of a plurality of pixels included in a region of a predetermined size that includes a pixel of interest of image data obtained by reading a document on which a halftone-processed image has been printed, obtains a feature amount indicating a brightness of the region. The apparatus updates a difference between the obtained feature amount and an index value corresponding to the obtained degree of variation in accordance with whether or not the difference is larger than a predetermined threshold, with respect to a plurality of index values respectively corresponding to a plurality of mutually different degrees of variation, decides a correction value of the pixel of interest using the updated difference and the index value, and corrects a value of the pixel of interest using the decided correction value.

A target area of image data of a scanned document is set, in which the target area has a predetermined size and a target pixel, characteristic amounts indicating the brightness at two pixels among the plurality of pixels included in the set target area are obtained, a determination is made on whether or not the difference between the obtained characteristic amounts indicating the brightness is higher than a threshold, a brightness correction amount is decided based on a characteristic amount indicating the brightness of the target pixel and the result of the determination, and the brightness characteristic amount indicating the brightness of the target pixel is corrected based on the decided correction amount.

A method of generating an image on a transparent or semitransparent substrate, the method comprising analyzing a first image to be printed on a first side of the substrate to identify a region associated with a predominant color, printing, on the first side of the substrate a color patch with the identified predominant color, printing, on a second side of the substrate, a test color pattern overlapping with the color patch on the first side of the substrate, determining, in a transmission geometry, a color distribution in the color patch, and generating from the determined color distribution, for the region associated with the predominant color identified in the first image, a transmission mode color profile for printing on the second side of the substrate.

According to one embodiment, an image processing apparatus includes a scanner to generate image data by scanning a document and a control unit. The control is configured to set, for each pixel in the image data, a second pixel value based on a first pixel value and a difference between a first base value corresponding to a base color of the document and a second base value that is based on neighboring pixel values around the pixel. A correction table is used to obtain a corrected second pixel value for each pixel. A third pixel value for each pixel is set based on the corrected second pixel value and the difference between the first and second base values.

A method of generating an image on a transparent or semitransparent substrate, the method comprising analyzing a first image to be printed on a first side of the substrate to identify a region associated with a predominant color, printing, on the first side of the substrate a color patch with the identified predominant color, printing, on a second side of the substrate, a test color pattern overlapping with the color patch on the first side of the substrate, determining, in a transmission geometry, a color distribution in the color patch, and generating from the determined color distribution, for the region associated with the predominant color identified in the first image, a transmission mode color profile for printing on the second side of the substrate.