An image forming apparatus comprises: an image processor to convert image data based on a conversion condition; an image forming unit to form an image based on the converted image data using a replaceable member; a memory to store the image data and the converted image data; a sensor to perform measurement on a test image; and a controller. If the replacement of the replaceable member is detected while forming images, the controller controls the image forming unit to form the test image and generates the conversion condition based on a result of the measurement on the test image. If the replacement of the replaceable member is detected while forming the images, the controller further controls the image processor to convert the image data stored in the memory based on the generated conversion condition.

A print apparatus is disclosed. In some examples, the print apparatus comprises a print head to deposit print agent onto a substrate; a detector to detect a fiducial; a first light source to back-illuminate the substrate, such that light from the first light source is to be detected by the detector through the substrate; and processing apparatus. The processing apparatus is to operate the print head to deposit print agent to form a first fiducial on a first side of the substrate, the first fiducial comprising a shape of a first colour and having a first dimension, and a background of print agent of a second, different colour, wherein the first dimension of the shape does not exceed a corresponding dimension of the background; operate the print head to deposit print agent to form a second fiducial on a second, opposite side of the substrate, the second fiducial comprising an inverted version of the shape of the first colour; operate the first light source to back-illuminate the substrate; operate the detector to detect the first and second fiducials; and determine whether the first fiducial is aligned with the second fiducial. A method and a machine-readable medium are also disclosed.

A first surface of a first sheet has a second image formed in advance. An image forming system generates reference data based on a result of reading an image on the first surface of the first sheet on which a first image is not formed, generates first image data that represents a result of reading an image on the first surface of the first sheet having the first image formed on the first surface, and determines, based on the reference data and the first image data, a relative position between the first image and the second image on the first surface of the first sheet.

A color conversion apparatus includes a hardware processor that obtains a scanner profile created on the basis of measured RGB values and corresponding measured colorimetric values of patches in a first color chart, and creates a table including correction amounts of RGB values, each according to the level of flare estimated for a patch and each associated with an RGB-value difference and a patch-size difference, on the basis of RGB values of patches in the first color chart and RGB values of patches in a specific chart. The specific chart is created by using a part of the patches in the first color chart with the RGB value or patch size being changed. The hardware processor further corrects measured RGB values of patches in a second color chart with the table, and convers the corrected RGB values into colorimetric values with the scanner profile.

A method for printing defect detection includes processing and analyzing a difference image obtained by comparing an image scanned with a verifier to a reference image. The detected defects are grouped, and the grouping is refined. Confidence level values are then assigned to the refined groups, and analysis is performed to determine if one or more servicing actions should be taken.

The recording device includes an upstream transport roller pair capable of transporting a medium, a recording head configured to record an image by discharging ink at a predetermined timing on the medium transported downstream in a Dl direction by a predetermined transport amount by the upstream transport roller pair while moving in a Y-axis direction intersecting the D1 direction, an image capturing unit configured to read the image recorded on the medium by the recording head, and a control unit, wherein the control unit has a function of performing maintenance for a discharge failure of the ink, a correction of the transport amount, and a correction of the discharge timing of the ink based on the reading result of the image read by the image capturing unit.

An inspection apparatus for detecting a difference between image data obtained by reading a sheet, and a reference image of the image data. The inspection apparatus obtains first image data by reading a sheet having a patch image printed thereon, obtains second image data from print data of the patch image, performs edge correction on a line included in the second image data by applying an edge correction parameter, and obtains an edge correction parameter that minimizes a difference between the density of the second image data subjected to the edge correction and the density of the first image data, and stores the obtained edge correction parameter.

An image forming apparatus comprising: an image forming unit configured to convey a recording medium, and form an image on the recording medium based on an image forming condition; and a controller configured to control the image forming unit to form a test image and a scale image extending a conveyance direction in which the recording medium is conveyed, obtain user instruction information related to a density fluctuation of the test image in the conveyance direction, and to generate the image forming condition to suppresses image density unevenness in the conveyance direction to an image to be formed by the image forming unit based on the user instruction information.

An image forming apparatus includes an image forming unit to form an image on a sheet, a conveyance unit to convey the sheet having the image formed thereon to a conveyance path and a reading unit to read a test image of a sheet conveyed to the conveyance path. In addition, a controller determines an adjustment value for adjusting a geometric characteristic of an image to be formed by the image forming unit based on a reading result of the reading unit, controls the image forming unit to form the test image, controls the reading unit to read the sheet having the test image formed thereon, and determines an adjustment value for adjusting a geometric characteristic of an image to be formed by the image forming unit based on a reading result of the reading unit.

Techniques for characterizing an optical system (for example, a printer verifier) are provided. In this regard, the optical system may be characterized for scanning a printed image. The characterization of the optical system includes determining an effective aperture size of the optical system, and correspondingly an effective resolution at which the optical system can be configured to scan a portion of the printed image according to verification requirements.