An image reading apparatus includes an image capturing module, a reference member, a light source for emitting light to the reference member, a foreign object determining module for determining whether or not a foreign object appears in a specific image, and a position determining module for determining whether the foreign object exists on the image capturing module side or on the reference member side, based on an absolute value of a difference between a gradation value in a region included in two images and corresponding to a region where the foreign object appears when the foreign object appears in the specific image. One image is an image of the reference member captured under illumination of light with a first light quantity from the light source, and other image is an image of the reference member captured under illumination of light with a second light quantity from the light source.

An external security paper detection unit, an image-forming apparatus having the external security paper detection unit, and an image-forming method related to the apparatus. The external security paper detection unit includes a paper stack unit in which sheets of paper are stacked in order to feed the paper, a paper feed unit for feeding the paper stacked in the paper snick unit, a security paper detection unit for detecting whether moving paper is security paper or not, and a unit controller for normally supplying the moving security paper to a manual feed tray if the paper feed unit operates and a security paper detection signal is input from the security paper detection unit, whereby an image is formed only on the security paper, thus preventing the illegal leakage of documents.

An image reading apparatus which is capable of, even when there are foreign objects on a reading glass, determining a position unlikely to be adversely affected by the foreign objects as a reading position and reading an image. An original is conveyed to a reading area on the reading glass, and a reading unit reads the original at a reading position within the reading area. Foreign objects adhered to a plurality of candidate reading positions are detected using image data read at the plurality of candidate reading positions within the reading area by the reading unit in a state where the original is not being conveyed. A density of the foreign objects is measured, and a reading position at which the original is read is selected from among the candidate reading positions according to the density of the foreign objects.

An image reading apparatus that can, even when foreign matter exists on an original platen glass, determine a position less affected by the foreign matter, as an image reading position. In the image reading apparatus, an original is conveyed to a reading area on the original platen glass, and a reading unit reads the original at a reading position within the reading area. Image data is read at a plurality of candidate reading positions within the reading area in a state where the original is not conveyed, and foreign matter adhering to the candidate reading positions is detected. The number of pieces and the size of each piece of the detected foreign matter are measured, and a reading position for reading the original is determined from the plurality of candidate reading positions using a result of the measurement.

A control device estimates a color verification result by using the following method. The method includes obtaining a first set of color values by using measurements of a color chart printed by a printer without color management; calculating second and third sets of color values based on increased color gamut and reduced color gamut of the printer due to a conditional change of the printer; creating a first to third printer-profiles by using the first to third sets of color values; calculating theoretical reference values of target color values and first to third theoretical color values by using the first to third printer-profiles; calculating first to third color differences by using the theoretical reference values and the first to third theoretical color values; obtaining an estimated result of the color verification by comparing the first to third color differences with a preset standard value; and outputting the estimated result.

A system and method of detecting the presence of metallic objects in media to be conveyed in a medium transport system is disclosed. One or more metal detectors are included in the medium transport system to detect the presence of metal in the medium being transported. Signals from the metal detectors are sent to a system processor, which analyzes the signals, and produces proximity, duration, and/or intensity values therefrom. One or more microphones may also be included which detect the sound created as the medium is being transported. The processor computes sound values from the microphone signals, and analyzes the computed sound values along with the proximity, duration, and/or intensity values in order determine if the conveyance of the medium along the transport path should be stopped due to the presence of metal in the media or a jam occurring within the medium transport path.

A medium accommodating device includes: a loading unit on which media are loadable in an up-down direction; an air supply unit that supplies air to plural media loaded on the loading unit to float and separate the plural media; a sending unit that sequentially sends the media that are floated and separated by the air supply unit; a photographing unit that photographs a state in which the media are floated and separated by the air supply unit; an irradiation unit that irradiates side portions of the media with light; and an adjusting unit that adjusts an angle of the light irradiating the media from the irradiation unit.

An image processing apparatus includes a color stabilization processing unit and a display control unit. The color stabilization processing unit is configured to determine a correction amount of gradation of image data to be printed, based on a read image obtained by reading a recording medium as a print processing result. The display control unit is configured to display information indicating the correction amount.

A printing system is disclosed. The printing system includes a printer controller to receive optical density (OD) measurement data corresponding to application of a halftone pattern using ink on a medium in a printing system and calculate a predicted OD versus normalized ink coverage relationship for the printing system based on the received OD measurement data.

According to one embodiment, an image reading apparatus includes: a first illumination device for irradiating light at a first angle onto a sheet that is being conveyed; a second illumination device for irradiating light at a second angle onto the sheet that is being conveyed; illumination controllers for switching between a first irradiation state in which light is irradiated from the first illumination unit and the second illumination unit onto the sheet and a second irradiation state in which light is irradiated from only either the first illumination device or the second illumination device to the sheet; an imaging device for acquiring a first comparable image in the first irradiation state and for acquiring a second comparable image in the second irradiation state; and a defect detector for detecting a defect of the sheet based on the difference between the first comparable image and the second comparable image.