An image reading device includes: an image reading unit configured to, in a process of reciprocating relative to a fixed document, read a document image using one or a plurality of reading colors, and when a plurality of reading colors are used, read the document image while successively switching the reading colors in a process of moving; a moving unit configured to move the image reading unit; a moving speed changing unit configured to change moving speeds of the image reading unit in an outgoing path and a return path based on a number “N” (where N is a positive integer) of the reading colors by the image reading unit; and a reading color number changing unit configured to change reading color numbers of the image reading unit in the outgoing path and the return path based on the number “N” of the reading colors.

An internal discharge space is defined between an image reading section and an image forming section and the internal discharge space has an opening in a front of the image forming apparatus. Since the internal discharge space has the opening in the front of the image forming apparatus, a border between the internal discharge space and the housing is located in the front of the image forming apparatus. A light emitting section having a predetermined length along the border is provided and emits light along the predetermined length of the border, enabling users to check a light emission state from a distance. Accordingly, a state of the image forming apparatus can be indicated by the light emitting section.

An image processing portion of an image reading apparatus includes an extraction portion that extracts color information, a management portion that manages management color information that is an estimated value of the color information based on a control signal, a determination portion that determines whether or not the color information matches the management color information, and a writing control portion that causes the storage portion to store the pixel data when it is determined that the color information matches the management color information and that does not cause the storage portion to store the pixel data when it is determined that the color information does not match the management color information. When the color information does not match the management color information, the management portion adjusts the management color information to match the color information.

A device including an array of pixels and a filter wheel may capture a plurality of images by exposing the array of pixels. The device may spin, while capturing the plurality of images, the filter wheel, and the filter wheel may include filter segments. In some implementations, a portion of the filter wheel in front of the array of pixels includes two or more filter segments.

An image processing apparatus includes circuitry to receive visible image data obtained by reading of a subject with a sensor having sensitivity to visible light in a visible wavelength range and invisible image data obtained by reading of the subject with a sensor having sensitivity to invisible light in an invisible wavelength range. The circuitry generates image data for displaying, in a designated color, a portion of the visible image data corresponding to a designated region of the invisible image data. The designated region has an absorption rate equal to or higher than a predetermined absorption rate.

An internal discharge space is defined between an image reading section and an image forming section and the internal discharge space has an opening in a front of the image forming apparatus. Since the internal discharge space has the opening in the front of the image forming apparatus, a border between the internal discharge space and the housing is located in the front of the image forming apparatus. A light emitting section having a predetermined length along the border is provided and emits light along the predetermined length of the border, enabling users to check a light emission state from a distance. Accordingly, a state of the image forming apparatus can be indicated by the light emitting section.

An image processing apparatus performs: acquiring target image data representing a target image including a plurality of pixels, the target image data including a plurality of sets of component image data representing respective ones of a plurality of component images; smoothing the plurality of component images to generate respective sets of a plurality of sets of smoothed component image data representing respective ones of a plurality of smoothed component images; enhancing an edge in each of the plurality of smoothed component images to generate corresponding one set of a plurality of sets of enhanced component image data; generating single-component image data including one type of component value corresponding to each of the plurality of pixels by using the plurality of sets of enhanced component image data; and specifying a plurality of edge pixels using the single-component image data, the plurality of edge pixels constituting an edge in the target image.

An image processing device includes: an estimated size setting section (ACS determination section 151) which sets a document size of a document sheet as an estimated size; a threshold deciding section (ACS determination section 151) which decides a first threshold according to the estimated size; and an ACS determination section (151) which determines that the document sheet is a color document sheet when a number of color pixels reaches the first threshold. When an actual size of the document sheet is smaller than the estimated size, the threshold deciding section decides a second threshold which is smaller than the first threshold, and the document sheet is determined to be a color document sheet when the number of color pixels is the second threshold or greater and is determined to be a black-and-white document sheet when the number of color pixels is smaller than the second threshold.

An image acquisition apparatus comprising pixels each including sub-pixels, the apparatus comprising signal holding units for holding signals from the sub-pixels, and a signal processing unit for acquiring and processing each of the signals from the signal holding units, wherein the signal processing unit includes a first mode of amplifying, by a predetermined amplification factor, the signals held by the signal holding units and individually outputting the signals, and a second mode of amplifying, by amplification factors at least some of which are different from the amplification factor in the first mode, the signals held by the signal holding units to add and output the signals.

An original image is read as an aggregate of a plurality of pixels in which adjacent pixels have different colors (R, G, and B) in a main scanning direction and in a sub-scanning direction, and the read pixels of the respective colors are stored in a line memory in association with information on relative positions of the pixels with respect to another pixel. Then, the stored pixels are sorted so that pixels having the same color are adjacent to each other, and an abnormal pixel (dust) not present in the original image is detected based on the state of the sorted pixels. With this, the dust not present in the original image is detected without increasing the cost, and the dust is corrected without forming a conspicuous trace of correction.