An image reading apparatus includes: a sensor module which includes a light source and sensors; a reference member for creating black correction data and white correction data; and an image processor. The image processor corrects uneven density of an image resulting from interference of image signals from the sensors, by performing, on the image signals obtained by the sensors, shading correction using black correction data and white correction data. The image processor obtains causes the sensors to obtain image signals of the reference member, and creates the white correction data based on white data, and the black correction data based on intermediate data. At least one of when creating the white correction data and when creating the black correction data, the image processor causes the sensors to obtain image signals of the reference member a plurality of times.

An image reading apparatus includes: a sensor module which includes a light source and sensors; a reference member for creating black correction data and white correction data; and an image processor. The image processor corrects uneven density of an image resulting from interference of image signals from the sensors, by performing, on the image signals obtained by the sensors, shading correction using black correction data and white correction data. The image processor obtains causes the sensors to obtain image signals of the reference member, and creates the white correction data based on white data, and the black correction data based on intermediate data. At least one of when creating the white correction data and when creating the black correction data, the image processor causes the sensors to obtain image signals of the reference member a plurality of times.

A method and system of controlling at least one printbar in a printing system are described. The printing system has one or more of printbars (160, 190) distributed along a media transport. A first image including a reference pattern (240A, 240B) is generated on a print medium (150) with a first printbar (160). A detector (180) then detects a pattern on the print medium. The reference pattern and the detected pattern are used to determine a position of the first image relative to a second printbar (190). This position is used to configure nozzle data for a second image to be generated on the print medium by the second printbar.

Disclosed are methods and systems for compensating for process direction banding associated with a document processing system including a ROS. According to one exemplary embodiment, a ROS driver uses a plurality of beam delay/advance values to compensate for banding caused by an interaction of a halftone pattern and process direction density variations associated with the ROS.

A method and apparatus for subdividing and printing regions of a substrate with multiple print heads or multiple print head assemblies which substantially decreases printing time is described. The method includes a feathering method which reduces overlap artifacts which is useful in any printing situation where adjacent regions are printed that could be misaligned, offset, or have slightly different colors.

The present disclosure relates to devices and methods for acquiring an image having two-dimensional spatial resolution and spectral resolution. An example method comprises: acquiring a frame using rows of photo-sensitive areas on a sensor surface detecting incident light from an object imaged by an optical system onto an image plane, wherein rows of photo-sensitive areas are arranged to receive different wavelengths; moving the sensor surface in a direction perpendicular to a longitudinal direction of the rows; repeating the acquiring and moving for acquiring a plurality of frames recording different spectral information for respective positions on the object; and combining information from the plurality of frames to form multiple channels of an image, wherein each channel is formed based on detected light in respective rows and represent a two-dimensional image of the object for a different wavelength.

A method, and document scanner system, for correcting image values recorded by an optical document scanner with multiple color cameras arranged in a staggered configuration with overlap scan areas includes storing color correction values mapped to respective color index values, where a color correction value is computed from a color difference between a first color value and a second color value of the respective overlap sets, and correcting a third color value which is a color value from the second set of color image values by a color correction value which is looked up via a color index value determined from the third color value. Thereby color variations among staggered cameras are corrected.

An image reading device includes: a sensor module having a light source and a plurality of sensors; a white reference plate; and an image processor that generates correction data to be used for shading correction and performs the shading correction on image signals, using the correction data. The light source is configured to switch between at least a first luminous intensity and a second luminous intensity lower than the first luminous intensity. The image processor acquires intermediate data by causing the plurality of sensors to acquire an image signal of the white reference plate illuminated with the second luminous intensity, generates black correction data, based on the intermediate data, and performs the shading correction, using the black correction data, so that a density unevenness, in an image, caused by interference between image signals from the plurality of sensors.

An image reading apparatus includes: a sensor module which includes a light source and sensors; a reference member for creating black correction data and white correction data; and an image processor. The image processor corrects uneven density of an image resulting from interference of image signals from the sensors, by performing, on the image signals obtained by the sensors, shading correction using black correction data and white correction data. The image processor obtains causes the sensors to obtain image signals of the reference member, and creates the white correction data based on white data, and the black correction data based on intermediate data. At least one of when creating the white correction data and when creating the black correction data, the image processor causes the sensors to obtain image signals of the reference member a plurality of times.

An image reading device includes an image processor that generates correction data to be used for shading correction and perform the shading correction using the correction data, and a memory that stores first black correction data to be used for the shading correction in a main scanning direction in a predetermined first position in a predetermined sub-scanning direction. The image processor generates third black data based on an image signal of a second reference plate extending in the sub-scanning direction in a predetermined second position in the main scanning direction, generates black correction data according to the sub-scanning direction based on the first black correction data and the third black data, and performs the shading correction using the black correction data so as to correct density unevenness in the main scanning direction and the sub-scanning direction caused by an interference between image signals from a plurality of sensors.