A controller of an image reading device performs search for an edge candidate position inward from an edge portion in a main scanning direction of analysis image data in an extraction process of extracting a document region from read image data. When the retrieved edge candidate position corresponds to a dirt position, the search is continued whereas when the retrieved edge candidate position does not correspond to the dirt position, the document region is extracted from the read image data at the retrieved edge candidate position.

An image reading apparatus includes a conveyance unit configured to convey an original; a reading unit comprising a reading sensor, the reading sensor having a light receiving element to receive light of a first color and a light receiving element to receive light of a second color that is different from the first color, wherein the reading unit is configured to read an image of the original conveyed by the conveyance unit by using the reading sensor to generate image data which represents a reading result of the reading unit; at least one processor configured to: determine a first abnormal position that is a position in a first direction of an abnormal pixel of the first color in an image represented by the image data.

A reading device and an image forming apparatus are provided. The reading device includes an image reading device configured to read an image on a recording medium being conveyed, a background device serving as a background image when the image is read by the image reading device, and a foreign-object detector configured to compare a first read image obtained as the background device is read by the image reading device with a second read image obtained as the background device and the recording medium are read by the image reading device to detect an attached foreign object. The image forming apparatus includes the reading device and an image forming device.

For each region of interest (ROI) type of a number of ROI types, ROIs of the ROI type within a reference image are compared to corresponding ROIs within a test image corresponding to the reference image and printed by a printing device. For each ROI type, a feature vector characterizing image quality defects within the test image for the ROI type is generated based on results of the comparing for the ROI type. Whether print quality of the printing device has degraded below a specified acceptable print quality level can be assessed based on the feature vectors for the ROI types.

An image reading apparatus includes a light source to emit at least light in a first wavelength range and light in a second wavelength range, a background member having different light reflectances in the first and second wavelength ranges, an imaging device, and circuitry. The imaging device receives reflected light from the background member irradiated with the light in the first wavelength range, and generates first read information. The imaging device further receives reflected light from the background member irradiated with the light in the second wavelength range, and generates second read information. The circuitry detects presence or absence of a first foreign substance based on a difference in reading level of the first read information generated by the imaging device; and detect presence or absence of a second foreign substance based on a difference in reading level of the second read information generated by the imaging device.

An image reading apparatus includes an original tray on which an original is to be stacked; a conveyance unit configured to convey the original stacked on the original tray; a reading unit including a reading sensor having a light receiving element to receive light of a first color and a light receiving element to receive light of a second color that is different from the first color, wherein the reading unit is configured to read an image of the original conveyed by the conveyance unit by using the reading sensor to generate image data which represents a reading result of the reading unit; at least one processor configured to: determine a first abnormal position which is a position in a first direction of an abnormal pixel of the first color in the image represented by the image data, wherein, in the image represented by the image data.

A multifunction peripheral includes a conveyance roller, a print engine, a scanner, and a controller. The controller is configured to perform: driving the conveyance roller to convey a recording medium and controlling the print engine to record, on the recording medium, a test image based on test image data with recording agent; after recording the test image, controlling the scanner to generate scan data of the test image recorded on the recording medium; after generating the scan data, extracting, based on the scan data and the test image data, stain data indicative of a stain caused by transfer of the recording agent from the conveyance roller to the recording medium; after extracting the stain data, generating correction data by removing the stain data from the scan data; and executing particular processing by using the correction data.

A multi-mode scanning device for scanning an original includes a non-transparent element, a first light source, a second light source and an optical module. The first light source outputs visible light to irradiate the non-transparent element and the original to generate first light and second light, respectively. The second light source outputs invisible light to irradiate a combination of the non-transparent element and the original to generate third light and fourth light. The optical module receives the first light, the second light, the third light and the fourth light and generates sensing signals representative of visible light information and invisible light information of the original. The original is disposed between the non-transparent element and the optical module. The first light source and the optical module are disposed on a same side of the non-transparent element.

In an example method, an image of a printed document is descreened. The descreened image is separated into blocks. A smooth area of the descreened image is selected based on an averaging of localized color distance values of pixels in each of the blocks. A streak in a block of the smooth area is detected in response to detecting that a magnitude of a color distance projection of the block exceeds a threshold value.

An image reading apparatus includes a line sensor configured to read an image of a target object. The line sensor includes light receiving element arrays arranged at given intervals in a second direction perpendicular to a first direction for a plurality of lines, the plurality of light receiving element arrays each including a first light receiving element configured to receive light of a first color and a second light receiving element configured to receive light of a second color different from the first color, which are arranged in the first direction to form one line. The image reading apparatus is configured to derive a shading correction coefficient for shading correction based on output from the light receiving element arrays that have read a reference white plate, and to identify, as an abnormal pixel, a pixel obtained by reading a foreign matter existing on the reference white plate.