An image reading apparatus and an image forming system are provided which can reduce the influence of magnification error, detect patches in correct positions, and save the sheets required for adjusting an image. The image reading apparatus makes use of an image scanner which reads patches printed on a sheet P, a spectral colorimeter which colorimetrically measures the patches read by the image scanner, and is provided with a timing compensation unit which compensates the colorimetric measurement timing with which colorimetric operation of the spectral colorimeter is triggered based on the positional information of the patches read by the image scanner, and an image correction unit which corrects the color information of the patches read by the image scanner based on the colorimetric values of the patches colorimetrically measured by the spectral colorimeter.

A lighting device (23) irradiates a web under conveyance with light. The lighting device includes a light source (43), and an irradiation port (61) configured to open linearly in a widthwise direction of the web at an end portion facing the web. The irradiation port (61) is formed between first and second parallel portions (62b, 63b) where a first plate member (62) and a second plate member (63) parallelly face each other. The web under conveyance is irradiated with linear light. It is possible to provide a lighting device capable of irradiating only an inspection region of a sheet or a web with light.

An image forming apparatus includes a table generating unit. The table generating unit determines whether a target-value Voronoi region and a measured-value Voronoi region are identical or not. The table generating unit sets an output color value associated with a print position where the target-value Voronoi region and the measured-value Voronoi region are identical in the second color conversion table as the output color value associated with a specific input color value in the first color conversion table. The table generating unit sets the output color value associated with the print position where the target-value Voronoi region and the measured-value Voronoi region are different in the second color conversion table as a color value that is a color value in the hue plane and is different from the output color value associated with the specific input color value in the first color conversion table.

An information processing apparatus inspecting printed contents of a printed sheet, the information processing apparatus includes a recognition unit configured to recognize the printed contents printed on the sheet, an acquisition unit configured to acquire an attribute value from information recognized by the recognition unit, a specification unit configured to specify a time required for inspection of the printed contents of the sheet by using the attribute value acquired by the acquisition unit, and a notification unit configured to issue a notification to a user based on a result of comparison between the required time specified by the specification unit and a time limit for inspection of the printed contents.

The image processing apparatus includes: an abnormality detection unit configured to detect one or more abnormalities included in a target image and an abnormality exclusion processing unit configured to exclude a specific abnormality from the detected one or more abnormalities. In a case in which a detection area of a certain abnormality among the detected one or more abnormalities and a detection area of another abnormality overlap with each other and a type of the certain abnormality and a type of the another abnormality are different from each other, when brightness information of one of the certain abnormality and the another abnormality satisfies a specific condition, the abnormality exclusion processing unit excludes the one of the certain abnormality and the another abnormality from the detected one or more abnormalities.

An information processing apparatus includes circuitry. The circuitry acquires a first state parameter indicative of a state of a printer engine of an image forming apparatus. The circuitry performs comparison between the first state parameter acquired and each of second state parameters registered in a memory in advance and indicative of states of the printer engine of the image forming apparatus at creation of a plurality of color profiles. The circuitry searches for a color profile corresponding to a second state parameter closest to the first state parameter from among the second state parameters.

A measurement apparatus includes a light irradiator that irradiates a measurement target with light and a processor that controls the light irradiator, in which the processor is configured to irradiate a specific place of the measurement target with the light from plural places having different positions in one direction, and irradiate the specific place of the measurement target with the light from the plural places having different positions in a direction intersecting the one direction.

A method monitors a color standard for a machine for processing printing material. The color standard results from various parameters of the printing operation and correspondingly associated set points. The color standard may be modified and individually adapted to every machine. The machine is equipped such that current values of the parameters of the color standard are measured and forwarded to a computer. The computer compares these values and predefined set points of the color standard, and based on this information, makes an assessment of the color and quality level achieved in the printing operation. The computer outputs control signals based on the monitoring. The control signals influence the machine control and/or the determining of the current values of the parameters of the color standard in a feedback loop. The color standard is modifiable by the operator by a different selection and weighting of the parameters and the set points.

An image processing apparatus includes a decomposition unit configured to decompose a color image into at least two color component images, a first obtaining unit configured to obtain a skewness of a histogram corresponding to each of the color component images, and a determination unit configured to determine based on the obtained skewnesses associated with the color component images whether the color image is glossy.

An information processing apparatus obtains a plurality of scanned images, determines whether each of the plurality of scanned images is suitable for use in generating a reference image, by using a master image for generating the reference image, and generates the reference image by combining a plurality of scanned images determined to be suitable for use in generating the reference image.