A first zone and a second zone of a scan surface may be scanned by an image sensor. A lid may be coupled to the scan surface and have an open position and a closed position, the lid being to cover the first zone and the second zone when in the closed position. The position of a lid may be determined based on a comparison of a scan of the first zone and a scan of the second zone.

An image scanning apparatus includes an image sensor to scan a paper, a paper feeding apparatus to pick up a loaded paper and move the picked-up paper to a paper feeding path, a sensor to output a predetermined signal value when the paper is sensed at a predetermined position in the paper feeding path, and a processor to control the paper feeding apparatus to move the paper depending on a scan command. The processor confirms a length of the paper based on a signal sensed in the sensor, and controls the paper feeding apparatus to pick up the loaded paper based on the confirmed length.

An image forming apparatus includes processing circuitry and an image forming device. The processing circuitry is configured to acquire characteristic information of a recording medium measured, and apply a preset calculation criterion to the characteristic information to calculate an image forming condition. The image forming device is configured to form an image on the recording medium based on the image forming condition calculated by the processing circuitry.

A reading device includes a light source, an image sensor, a background board, and an image processing circuitry. The light source irradiates visible light and invisible light to a subject. The image sensor receives the visible light and the invisible light, each of which is reflected from the subject, to capture a visible image and an invisible image. The background board is provided in an image capturing range of the image sensor. The background board is a background portion. The image processing circuitry detects a feature amount of the subject and the background portion from at least one of the visible image and the invisible image.

An image processing apparatus includes a processor configured to: acquire image information obtained by an image reading apparatus including an illumination unit having an uneven balance in an amount of light in a sub-scanning direction; and specify a position of a folding line in a sheet from the acquired image information. The acquiring by the processor includes acquiring first image information obtained by reading the sheet in a first state in which the folding line in the sheet is positioned in a direction intersecting the sub-scanning direction of the image reading apparatus, and second image information obtained by reading the sheet in a second state in which the sheet is directed to an opposite side to a side in the first state. The specifying by the processor includes specifying the position of the folding line in the sheet based on the first image information and the second image information.

A document size detection device includes: a light source to irradiate a document with light; an imaging device to receive light reflected at the document; and circuitry to control switch on and off of the light source and movement in a sub-scanning direction of the light source, and determine a size of the document based on image data acquired by the imaging device. The circuitry is to determine a size in a main-scanning direction of the document based on: first image data acquired when the light source is switched off while the light source is at a first reading position; second image data acquired when the light source is switched on while the light source is at the first reading position; and third image data acquired when the light source is switched on while the light source is being moved from the first reading position to a second reading position.

Before reading of a document, an image processing control portion makes an image reading portion perform pre-scanning operation, which is scanning operation performed with a document cover open without a document placed on a placement surface, and checks the incident condition of external disturbance light on the image sensor. If it is judged that the incident condition is a predetermined state, the image processing control portion makes a control device perform a countermeasure process to make the room dimmer than it currently is.

A reflected light amount from a patch under a first light source is acquired, and a reflected light amount from the patch under a second light source whose wavelength band is different from the first light source is acquired. The type of a printing medium on which the patch is printed is determined based on the ratio of the two acquired reflected light amounts.

An image inspection device includes a hardware processor. The hardware processor (i) captures a read image from a reading device, (ii) compares a reference image and an inspection image obtained by reading a paper sheet targeted for inspection on which an image corresponding to the reference image has been formed with the reading device, to inspect the inspection image, (iii) sets a first alignment region having a predetermined width on a leading end side of each of the reference image and the inspection image in a conveyance direction, and sets a second alignment region having a predetermined width on a rear end side in the conveyance direction, and (iv) corrects the reference image on a basis of amounts of positional deviation of the first alignment region and the second alignment region.

A position detecting device includes an image sensor and circuitry. The image sensor is configured to read reflected light of light emitted from a light source onto a medium to be read. The circuitry is configured to perform black correction processing on an output signal of the image sensor using black correction data of the image sensor and detect a position of the medium from the output signal after the black correction processing.