An image-based acceptance learning device (2) learns a result of determination as to whether a planar object (1) is acceptable or defective based on at least one of a three-dimensional shape or a color on a surface of the planar object (1). The device (2) includes a surface image receiver (3) to receive an inputted two-dimensional data being image data of the surface of the planar object (1), a determination information receiver (4) to receive an inputted determination information indicating the result of determination as to whether the planar object (1) corresponding to the two-dimensional data is acceptable or defective, and a learner (5) to learn, based on the two-dimensional data and the determination information, a relevant area (1R) including the three-dimensional shape or the color on the surface in the two-dimensional data. The relevant area is a basis for the determination information.

An image processing apparatus that performs processes of reducing read data in a main-scanning direction and a sub-scanning direction, wherein the image reading apparatus includes a plurality of line image sensors having a longitudinal direction as the main-scanning direction, the plurality of line image sensors are displaced in the sub-scanning direction, and the image reading apparatus relatively moves the plurality of line image sensors and an original in the sub-scanning direction, wherein the image processing apparatus comprises: a sub-scanning direction processing unit configured to perform reduction processing in the sub-scanning direction; and a main-scanning direction processing unit configured to connect data after the reduction processing is performed by the sub-scanning direction processing unit in the main-scanning direction and reduces the connected data in the main-scanning direction.

An image processing apparatus that performs processes of reducing read data in a main-scanning direction and a sub-scanning direction, wherein the image reading apparatus includes a plurality of line image sensors having a longitudinal direction as the main-scanning direction, the plurality of line image sensors are displaced in the sub-scanning direction, and the image reading apparatus relatively moves the plurality of line image sensors and an original in the sub-scanning direction, wherein the image processing apparatus comprises: a sub-scanning direction processing unit configured to perform reduction processing in the sub-scanning direction; and a main-scanning direction processing unit configured to connect data after the reduction processing is performed by the sub-scanning direction processing unit in the main-scanning direction and reduces the connected data in the main-scanning direction.

An image processing apparatus comprises a storage unit configured to store image data read by scanning, with a linear sensor including pixels arranged in a main-scanning direction, an original in a sub-scanning direction orthogonal to the main-scanning direction, an acquisition unit configured to acquire inclination information indicating inclination of the image data; and a readout unit configured to read out the image data from the storage unit, with shifting, in accordance with the inclination information, a line position in the sub-scanning direction by each predetermined number of pixels in the main-scanning direction, wherein the readout unit reads out the image data from the storage unit, based on the inclination information, differentiating the predetermined number of pixels between an edge in the main-scanning direction and other parts.

An image processing apparatus comprises a storage unit configured to store image data read by scanning, with a linear sensor including pixels arranged in a main-scanning direction, an original in a sub-scanning direction orthogonal to the main-scanning direction, an acquisition unit configured to acquire inclination information indicating inclination of the image data; and a readout unit configured to read out the image data from the storage unit, with shifting, in accordance with the inclination information, a line position in the sub-scanning direction by each predetermined number of pixels in the main-scanning direction, wherein the readout unit reads out the image data from the storage unit, based on the inclination information, differentiating the predetermined number of pixels between an edge in the main-scanning direction and other parts.

There is provided a method of manufacturing an image sensor unit, the image sensor unit including: a linear light source that illuminates a document along a main scanning direction; a rod lens array that includes a plurality of rod lenses arranged in the main scanning direction and condenses a light reflected from the document; and a linear image sensor that receives a light condensed by the rod lens array. When a rod lens having an optically discontinuous portion on a surface and/or interior of the rod lens is included, the rod lens array is arranged such that the optically discontinuous portion is not located toward the document.

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.

There is provided a method of manufacturing an image sensor unit, the image sensor unit including: a linear light source that illuminates a document along a main scanning direction; a rod lens array that includes a plurality of rod lenses arranged in the main scanning direction and condenses a light reflected from the document; and a linear image sensor that receives a light condensed by the rod lens array. When a rod lens having an optically discontinuous portion on a surface and/or interior of the rod lens is included, the rod lens array is arranged such that the optically discontinuous portion is not located toward the document.

According to an embodiment, a reading device that reads an object to be read in an image forming apparatus includes a lens array and a light guide. The lens array is provided in a posture in which an optical axis follows a height direction intersecting a reading surface. The light guide is adjacent to the lens array in a sub-scanning direction intersecting both the height direction and a main scanning direction, and locates maximum illuminance of illumination light illuminating the object to be read on a side opposite to the lens array with respect to a deepest position of a depth of field of the lens array in the height direction.

An optical device includes a lens body including plural lenses of which optical axes are arranged alongside each other, and having an intermediate image forming surface for forming an erect real image of equal magnification formed in an optical path, a light shielding body that is provided to face a light incident surface of the lens body, and includes a transmitting portion that is positioned on the optical axes of the plural lenses and transmits light and a light shielding unit that is positioned on a portion other than the optical axes of the plural lenses and shields the passage of light, and a regulating body that is provided to face a light incident surface of the light shielding body, includes an opening narrower than the transmitting portion, and regulates a part of light toward the transmitting portion.