Provided is an image reading apparatus, including: a reading unit configured to read an original image of an original placed on an original table for each line in a main scanning direction; and a control unit. The control unit is configured to derive, from the original image read for a predetermined number of lines by the reading unit, a luminance difference value between luminance values of two pixels each separated by a first distance from a pixel of interest that is located at a predetermined position in the main scanning direction, and a difference value between a maximum luminance value and a minimum luminance value of pixels within a range of a second distance, which is larger than the first distance, from the pixel of interest.

An electronic device communicable with a server system via a network, includes circuitry to: transmit information on the electronic device to the server system; store in a memory information on a display component corresponding to the information on the electronic device that is acquired from the server system; read the information on the display component stored in the memory at a predetermined timing; display the display component that is read on a display; in response to selection of the display component, acquire information associated with the display component from the server system; and display the acquired information on the display.

An image processing apparatus includes a first detection unit and a second detection unit. The first detection unit detects a rectangular shape in an image including plural document images. The second detection unit detects, in a case where a background of the rectangular shape is not white, rectangular shapes included in the rectangular shape detected by the first detection unit as document images.

An image forming apparatus includes an obtaining unit configured to obtain information related to a resolution of an image to be formed, an image processing unit configured to execute image processing corresponding to the information on image data, an image forming unit configured to form an image based on the image data on which the image processing is executed by the image processing unit, an intermediate transfer member to which a measuring image formed by the image forming unit is transferred, a measurement unit configured to measure the measuring image transferred to the intermediate transfer member, a storage unit configured to store measuring image data, and a controller configured to control the image processing unit to execute first image processing on the measuring image data, control the image forming unit to form the measuring image, control the measurement unit to measure the measuring image, and control an image forming condition.

A printing apparatus includes a printer to print an image on a sheet, a conveying roller for conveying the sheet from the printer along a conveyance path, an optical sensor provided on the conveyance path, the optical sensor detecting the sheet being conveyed, a finisher to perform a finishing process on the conveyed sheet, based on detection information from the optical sensor, an operation panel operable to receive sheet type information about a transparency type of the sheet, and a controller (i) to control the finisher to perform the finishing process on the conveyed sheet if the sheet type corresponds to a first type of translucent sheet, and (ii) to control the operation panel to display a message indicating that the finishing processing cannot be performed if the sheet type corresponds to a second type of translucent sheet being different in transparency from the first.

An image processing apparatus includes a control unit configured to control execution of monochromatic calibration and multi-color calibration, and a registration unit configured to register paper types of paper to be used at time of execution of the monochromatic calibration, a monochromatic target value set for each of the paper types used for the monochromatic calibration, paper types of paper to be used at time of execution of multi-color calibration, and a multi-color target value set for each of the paper types used for the multi-color calibration. The image processing apparatus executes the multi-color calibration, after executing the monochromatic calibration, via the control unit by using paper of a paper type selected from common paper types out of the registered paper types and the monochromatic target value and the multi-color target value set for the selected paper type.

An image reading device includes: contact glass, a document reading section that reads a document loaded on the contact glass while a moving mechanism moves in a document reading direction, a reading control section that causes the document reading section to read the whole contact glass at a rate of once per a predefined number of times N1, a first contamination detection section, and a report section. The first contamination detection section detects, from image data of the whole contact glass obtained through the reading by the document reading section, contamination of the contact glass present in a region other than a region loaded with the document. The report section, upon detecting by the first contamination detection section the same contamination from all the pieces of image data obtained consecutively a predefined plural number of times M1, reports a user that the contamination is present on the contact glass.

The present printing system obtains a transparency of a sheet to be subjected to printing, and based on the obtained transparency of the sheet, restricts execution of post-processing by a discharging portion.

An image forming apparatus includes an image formation unit, a detection unit, a storage unit, and a control unit. When the detection unit outputs a second output value when a second recording material, which is different from a first recording material is detected, in a state where the storage unit stores a first output value output by the detection unit upon detection of the first recording material, the control unit controls an image forming condition based on at least the first output value if a differential value between the first output value and the second output value is smaller than a predetermined threshold value and controls the image forming condition based on the second output value without using the first output value if the differential value is greater than the predetermined threshold value.

An image processing apparatus incorporated in an image forming apparatus includes a data acquisition unit, a proofreading processing unit, and an image generating unit. The data acquisition unit acquires data to be proofread representing sentences that are targets of proofreading. The proofreading processing unit proofreads the data to be proofread acquired by the data acquisition unit, and detects an erroneous writing including an error, and a regular notation representing a correct form of the erroneous writing. The image generating unit synthesizes an image representing the erroneous writing and the regular notation detected through the proofreading process performed by the proofreading processing unit with the data to be proofread, to thereby generate a proofreading result image.