In an example method, a visually significant marking scheme is generated including a pattern of data marks and reference marks based on a received image to be printed, data information, and reference information. Data marks are generated based on the data information and the reference marks are generated based on the reference information. The image is printed including the data marks and the reference marks arranged based on the visually significant marking scheme onto the surface of the object.

Then image reading device includes a transparent document table, a frame, a reading unit, a moving mechanism, a white reference member, and a controller. The frame is provided around a peripheral of the document table. The white reference member is provided on the frame adjacent to the document table in the sub scanning direction and has a length in the main scanning direction longer than the document table. The reading unit includes a first reading part which reads an area corresponding to the document table and a second reading part which reads an area corresponding to the frame. The controller detects a boundary between the frame and the reference member based on a read value of the second reading part while moving the reading unit by the moving mechanism, and positions the reading unit at a home position apart from the boundary by a predetermined distance.

An image forming apparatus includes a mounting table on which an object whose image is to be scanned is mounted; an image forming section that forms an image, which includes a first image for measuring a relative position with respect to an end portion of a paper, on a first side of the paper; an image scanning section that scans the image mounted on the mounting table; and a position correction section that corrects a relative position of an image, which is formed on the paper, with respect to the paper based on a result of scanning performed by the image scanning section, in which in a case where the image scanning section scans the end portion of the paper and the image formed on the first side of the paper in a state in which the first side of the paper on which the first image is formed faces the mounting table, the end portion of the paper is mounted on the mounting table at a position separated from an end portion of the mounting table, and, further, the paper is covered with a cover paper, and the image forming section forms, on the first side of the paper, a third image that uses, as an alignment object, a second image for alignment formed on a side of the cover paper opposite to a side on which the cover paper is in contact with the paper while a part of the paper is mounted in a state of protruding from the mounting table and a first edge of the cover paper.

There is provided an image forming apparatus capable of preventing deterioration in accuracy of image position adjustment due to erroneous detection of a marker.

Examples of printing device calibration based on a lot code are described. In an example, a lot code of a print media is determined. Calibration parameters for a printing device are determined based on the lot code. The printing device is calibrated to print on the print media based on the calibration parameters.

An information processing apparatus includes: a processor is configured to: read an image of at least one of a first surface or a second surface of a medium with the medium folded; discriminate whether the image is of the first surface or the second surface based on an identification image in the image; specify, based on the image, a surface on which a folding deviation occurs; and determine a correction direction of the folding deviation according to whether the surface on which the folding deviation occurs is the first surface or the second surface.

An image processing apparatus having a reading device to read an image from a sheet includes one or more controllers to perform operations. One image is read from one sheet by using the reading device. Edge detection processing is executed on the one image. At least one pair of edges is determined from among a plurality of edges based on information of the plurality of edges detected in the edge detection processing and size information of the one sheet.

A position detection device includes a background member, a reader, and processing circuitry. The background member has a higher absorption characteristic in an invisible wavelength region than in a visible wavelength region. The reader opposite the background member irradiates a recording medium having a mark and the background member with light of a visible wavelength to output a visible image or with light of an invisible wavelength to output an invisible image. The processing circuitry is configured to: detect an end position of the recording medium and a position of the mark on the recording medium from a read image output from the reader; and select the visible or invisible image as the read image used for position detection, according to an absorption characteristic of a color material forming the mark read by the reader and an absorption characteristic of the recording medium in the invisible wavelength region.

An information processing apparatus includes: a processor is configured to: read an image of at least one of a first surface or a second surface of a medium with the medium folded; discriminate whether the image is of the first surface or the second surface based on an identification image in the image; specify, based on the image, a surface on which a folding deviation occurs; and determine a correction direction of the folding deviation according to whether the surface on which the folding deviation occurs is the first surface or the second surface.

In one example, a device to transfer multiple first positions of an edge guide movable back and forth across a print media input tray to corresponding multiple second positions of an optical marker movable back and forth along a scan line next to a scan bed located near the input tray. The device includes a first part connected to or integral with the edge guide, a second part connected to or integral with the marker, and a mechanical link linking the first part and the second part to convert linear motion of the edge guide back and forth across the tray to linear motion of the marker back and forth along the scan line.