Abstract: An image processing device includes: a first contamination detection circuit to detect contamination on an image reading device using a first relative threshold value calculated from a standard deviation of pixel values of a same-density region in a read image obtained by the image reading device, the image reading device reading a reference image formed on a recording medium by a line head including a plurality of inkjet heads and that has density regions of a plurality of gradations; a second contamination detection circuit to detect contamination on the image reading device using a second relative threshold value calculated from a standard deviation of pixel values of an area in the read image, the area being divided for each of the plurality of inkjet heads; and a contamination processing circuit to eliminate an influence of the contamination on the read image when at least one of the first contamination detection circuit or the second contamination detection circuit determines the contamination.

Abstract: A liquid discharge apparatus according to an aspect of the present disclosure is a liquid discharge apparatus for forming an image on a recording medium, the liquid discharge apparatus including a first image obtaining unit configured to obtain first image data, a second image generating unit configured to generate second image data by adding a predetermined figure to the first image data, a correcting unit configured to generate third image data obtained by correcting, for each of pages, the first image data, based on the second image data and read image data obtained by reading an image formed on the recording medium based on the second image data, and a liquid discharging unit configured to discharge liquid onto the recording medium, based on the third image data.

Abstract: A printing apparatus includes a printing device to print, on a sheet, a detection mark for acquiring an amount of deviation of an image, a detection device to read a position of the detection mark and acquire the amount of deviation of the position of the detection mark, and control circuitry to perform correction according to the amount of deviation. The circuitry prints the detection marks on both faces of the sheet in duplex printing, reads the detection marks on both faces with the detection device, calculates a first correction value from the position of the detection mark on a first face on which printing is performed first, calculates a second correction value from the position of the detection mark on a second face on which printing is performed later, and calculates a third correction value from the positions of the detection marks on the first and second faces.

Abstract: A printing apparatus includes a printing device to print, on a sheet, a detection mark for acquiring an amount of deviation of an image, a detection device to read a position of the detection mark and acquire the amount of deviation of the position of the detection mark, and control circuitry to perform correction according to the amount of deviation. The circuitry prints the detection marks on both faces of the sheet in duplex printing, reads the detection marks on both faces with the detection device, calculates a first correction value from the position of the detection mark on a first face on which printing is performed first, calculates a second correction value from the position of the detection mark on a second face on which printing is performed later, and calculates a third correction value from the positions of the detection marks on the first and second faces.

Abstract: An image forming system includes an image forming device configured to form an image on a recording medium, a reading device configured to read the image formed on the recording medium by the image forming device, and circuitry. The circuitry is configured to control the reading device; calculate a density of each predetermined unit area of the read image; determine whether the read image includes a region satisfying a predetermined density condition based on the calculated density; and output an image of a first region of the read image not satisfying the predetermined density condition, an image of a second region satisfying the predetermined density condition, and a visual representation associated with the second region in response to a determination that the read image includes the second region.

Abstract: An image forming system includes an image forming device configured to form an image on a recording medium, a reading device configured to read the image formed on the recording medium by the image forming device, and circuitry. The circuitry is configured to control the reading device; calculate a density of each predetermined unit area of the read image; determine whether the read image includes a region satisfying a predetermined density condition based on the calculated density; and output an image of a first region of the read image not satisfying the predetermined density condition, an image of a second region satisfying the predetermined density condition, and a visual representation associated with the second region in response to a determination that the read image includes the second region.

Abstract: An image processing device includes a label memory to store a first label assigned to a pixel in a previous line of a processing target image subjected to an assignment process prior to the assignment process on a processing target line of the processing target image, a label area memory to store identification information identifying a label area including pixels assigned with an identical label, and circuitry to, if at least one target pixel in the processing target line is an effective pixel, perform the assignment process on the target pixel based on at least one label that includes the first label and is assigned to at least one peripheral pixel peripheral to the target pixel, and to perform an updating process of updating the identification information based on a position of the target pixel and the label assigned to the target pixel.

Abstract: An image processing device includes a label memory to store a first label assigned to a pixel in a previous line of a processing target image subjected to an assignment process prior to the assignment process on a processing target line of the processing target image, a label area memory to store identification information identifying a label area including pixels assigned with an identical label, and circuitry to, if at least one target pixel in the processing target line is an effective pixel, perform the assignment process on the target pixel based on at least one label that includes the first label and is assigned to at least one peripheral pixel peripheral to the target pixel, and to perform an updating process of updating the identification information based on a position of the target pixel and the label assigned to the target pixel.