An image forming apparatus capable of preventing misdetermination of a type of printing paper includes a transmitted light receiver, a specularly reflected light receiver, and a diffusively reflected light receiver, which constitute a sensor, and an output determiner that determines whether data output by the plurality of light receivers is normal. The image forming apparatus determines the type of printing paper and an abnormality of the printing paper from the determination by the output determiner.

An image reading device includes: a reading unit; a first detecting unit that detects a position of the reading unit in the sub-scanning direction; a second detecting unit that detects a position of the reading unit in the sub-scanning direction; and a calculating unit that calculates a skew quantity and a skew direction of the reading unit, based on a difference, introduced by the skew, between a travel distance by which the reading unit has travelled from a measurement reference position located on an upstream side of the first detecting unit and the second detecting unit in a moving direction to a point where the reading unit is detected by the first detecting unit, and a travel distance by which the reading unit has travelled from the measurement reference position to a point where the reading unit is detected by the second detecting unit.

An image processing apparatus includes a presumed background region extractor for extracting a presumed background region presumed to include an image of a background from an input image, a threshold value determination module for determining a threshold value based on pixels in the presumed background region, an edge pixel extractor for using the threshold value to extract edge pixels from the input image, and a document region detector for detecting a document region from the edge pixels.

An image processing device includes an external memory interface to write image data to an image memory, and an inclination correction circuit. The inclination correction circuit generates coordinate information based on inclination information, detects, from the coordinate information, a minimum sub-scanning coordinate in each of divided areas of the image data, generates first read addresses for reading the divided areas of the image data from the image memory based on the minimum sub-scanning coordinate, reads the divided areas of the image data from the image memory based on the first read addresses, writes the divided areas of the image data to an internal memory, generates second read addresses for reading the divided areas of the image data from the internal memory based on the coordinate information, and reads the divided areas of the image data from the internal memory based on the second read addresses.

An image reading device generates, as image data of a reading region, image data for output and image data for size detection, the latter having a lower resolution than the former, discriminates high density lines from the size-detection image data, sets as a target line one of the high density lines. And the image reading device calculates as a width for size detection a width from a reference line to the target line, sets as the size of a document a reference size that has a width closest to the width for size detection, performs image processing on the output image data based on the reference size set as the size of the document, and outputs the processed image data.

An image scanning apparatus performs operations including: upon detection of a first angle, causing light to be emitted to an original and recording a distribution of reflected light of the emitted light as first read data; upon elapse of a predetermined time from detection of a second angle, causing light to be emitted to the original and recording a distribution of reflected light of the emitted light as second read data; detecting a closed state of a pressure plate based on the second read data; and upon determination of an angle of the pressure plate with respect to the platen being equal to or smaller than a third angle smaller than the second angle in the detection of the closed state, detecting a width of the original in an opening-closing direction of the pressure plate based on a difference between the first and second read data.

An image reading apparatus that makes it possible to reduce the influences of dirt on a white reference chart itself, stripes caused by dust, and the like, and thereby generate accurate data for shading correction. An image processor performs shading correction on image data read by a reader unit. The read image data is compared with threshold values set for each pixel, and a pixel which is out of a range of the threshold values is determined as a singular point pixel. Data of a pixel determined as a singular point pixel is interpolated from data around the singular point pixel. Data of a pixel which is not determined as a singular point pixel is adopted as valid shading correction data. An operation controller controls the number of effective sampling lines from start to termination of sampling to be performed.

A first document image is scanned from a document in a first orientation, and a second document image is scanned from the document in a second orientation different from the first orientation. A wrinkle area candidate detecting unit rotates the first document image by a rotation angle between the first and second orientations, and detects as a wrinkle area candidate an object in a predetermined density range in the rotated first document image and the second document image. A similarity degree determining unit determines a similarity degree between the wrinkle area candidate of the rotated first document image and the corresponding wrinkle area candidate of the second document image. A wrinkle area removing unit removes the wrinkle area candidate as a wrinkle area if the similarity degree falls into a predetermined range.

A method of calibrating a beam scan field of an additive manufacturing machine in which a radiant energy beam is used to selectively melt material to form a workpiece, the method including: using a radiant energy source, directing a beam using a steering mechanism so as to create a calibration build job on a substrate, the calibration build job including at least one measurement artifact created by the beam; using a calibrated camera, collecting an image of the calibration build job; generating a set of measurements of the calibration build job from the image; comparing the measurements to a standard; in response to the measurements deviating from the standard by more than a predetermined acceptable tolerance, adjusting the steering mechanism; wherein the steps of directing, collecting, generating, comparing, and adjusting are carried out in response to automated commands from an electronic controller.

A method comprising obtaining, by a first information processing apparatus, a first electronic document to be formed: obtaining, by said first information processing apparatus, at least one identifier, each of said at least one identifier corresponding to a respective content to be formed as part of said first electronic document, and each of said at least one identifier having one or more associated locations indicating where on said first electronic document said corresponding content is to be formed: sending document information, by said first information processing apparatus, to an image forming apparatus and a second information processing apparatus, said document information comprising: said first electronic document, for each of said at least one identifier, said one or more associated locations, and, for each of said at least one identifier, said corresponding content or said identifier: obtaining, by said image forming apparatus and said second information processing apparatus, based on said document information, a second electronic document, said second electronic document being generated by, for each of said at least one identifier, retrieving said corresponding content, and including into said first electronic document, said corresponding content in association with said one or more associated locations: forming, by said image forming apparatus, a physical document from said second electronic document: obtaining, by said second information processing apparatus, an image of said physical document: comparing, by said second information processing apparatus, said second electronic document and said image to detect whether a difference exist: and sending, by said second information processing apparatus, a comparison result to said image forming apparatus, said comparison result including, if a difference is detected, information for causing said image forming apparatus to interrupt an operation and display said comparison result on a display unit. A computer program, an information processing apparatus, a system are also disclosed.