Techniques are described for dynamically correcting image distortion during imaging of a patterned sample having repeating spots. Different sets of image distortion correction coefficients may be calculated for different regions of a sample during a first imaging cycle of a multicycle imaging run and subsequently applied in real time to image data generated during subsequent cycles. In one implementation, image distortion correction coefficients may be calculated for an image of a patterned sample having repeated spots by: estimating an affine transform of the image; sharpening the image; and iteratively searching for an optimal set of distortion correction coefficients for the sharpened image, where iteratively searching for the optimal set of distortion correction coefficients for the sharpened image includes calculating a mean chastity for spot locations in the image, and where the estimated affine transform is applied during each iteration of the search.

Techniques are described for dynamically correcting image distortion during imaging of a patterned sample having repeating spots. Different sets of image distortion correction coefficients may be calculated for different regions of a sample during a first imaging cycle of a multicycle imaging run and subsequently applied in real time to image data generated during subsequent cycles. In one implementation, image distortion correction coefficients may be calculated for an image of a patterned sample having repeated spots by: estimating an affine transform of the image; sharpening the image; and iteratively searching for an optimal set of distortion correction coefficients for the sharpened image, where iteratively searching for the optimal set of distortion correction coefficients for the sharpened image includes calculating a mean chastity for spot locations in the image, and where the estimated affine transform is applied during each iteration of the search.

A recording system for recording a recording image based on image data by repeating a pass operation in which a nozzle column discharges ink while reciprocating relatively to a recording medium in a main scanning direction to form dots on the recording medium, and a conveying operation of relatively moving the nozzle column and the recording medium in a sub-scanning direction crossing the main scanning direction, the recording system including an assigning section for obtaining a plurality of halftone data which is generated with respect to the same area of the image data based on the image data, and which corresponds to the ink of a predetermined color, and then assigning each of the halftone data obtained to the pass operations in the same direction in reciprocation in the main scanning direction in a predetermined recording area.

An image reading device includes a reading unit that reads a document sheet and a reading standard surface and outputs read values corresponding to pixels arranged in a main scan direction, a control unit that processes the read values, and a storage unit storing information to be referenced by the control unit. In the storage unit, first data that is read values of the reading standard surface and serves as standards, and second data on ranges of variation, based on a change in a temperature, in the read values are stored. The control unit determines, based on the first data and the second data read from the storage unit and third data obtained by reading the reading standard surface after an acquisition of the first data, whether an abnormality exists in the pixels.

An image reading device includes a reading unit that reads a document sheet and a reading standard surface and outputs read values corresponding to pixels arranged in a main scan direction, a control unit that processes the read values, and a storage unit storing information to be referenced by the control unit. In the storage unit, first data that is read values of the reading standard surface and serves as standards, and second data on ranges of variation, based on a change in a temperature, in the read values are stored. The control unit determines, based on the first data and the second data read from the storage unit and third data obtained by reading the reading standard surface after an acquisition of the first data, whether an abnormality exists in the pixels.

An image reading apparatus is provided with: a reading processing unit which moves a reading unit, causes a light emitting unit to emit a first amount of light, reads an electric charge generated by a photoelectric conversion unit, and reads an image of a document placed on a document placing surface on the basis of the read electric charge; and a detection processing unit which causes a light emitting unit to emit a second amount of light greater than the first amount of light, reads an electric charge generated by the photoelectric conversion unit, and detects the size of the document placed on the document placing surface on the basis of the read electric charge.

A measurement apparatus includes a light irradiator, a light receiver, and a processor. The light irradiator is able to apply light from multiple directions to a specific portion of a subject to be measured. The light receiver receives light reflected by the specific portion. The processor is configured to: cause the light irradiator to apply light to the specific portion sequentially from the multiple directions; and acquire information concerning a tilt of a surface of the specific portion, based on information on light received by the light receiver when light is applied to the specific portion from a first direction and information on light received by the light receiver when light is applied to the specific portion from a second direction. The multiple directions include the first and second directions.

A measurement apparatus includes a light irradiator, a light receiver, and a processor. The light irradiator is able to apply light from multiple directions to a specific portion of a subject to be measured. The light receiver receives light reflected by the specific portion. The processor is configured to: cause the light irradiator to apply light to the specific portion sequentially from the multiple directions; and acquire information concerning a tilt of a surface of the specific portion, based on information on light received by the light receiver when light is applied to the specific portion from a first direction and information on light received by the light receiver when light is applied to the specific portion from a second direction. The multiple directions include the first and second directions.

An image reading apparatus includes a stacking unit, a conveyance unit to convey stacked sheets, a reading unit, a white reference plate provided in a second position, and a processor. The reading unit is movable and, at a first position, reads a conveyed sheet image to obtain image data and, at the second position, reads the white reference plate. The processor generates, based on a plate reading result, a shading correction value and corrects the image data using the shading correction value. Based on whether the number of times in which reading the white reference plate has been performed is less than a predetermined number of times, the reading unit changes a time interval in a reading period that is from a first timing to a second timing. The processor generates, each time the white reference plate is read, the shading correction value based on the plate reading results.

An image reading apparatus includes a stacking unit, a conveyance unit to convey stacked sheets, a reading unit, a white reference plate provided in a second position, and a processor. The reading unit is movable and, at a first position, reads a conveyed sheet image to obtain image data and, at the second position, reads the white reference plate. The processor generates, based on a plate reading result, a shading correction value and corrects the image data using the shading correction value. Based on whether the number of times in which reading the white reference plate has been performed is less than a predetermined number of times, the reading unit changes a time interval in a reading period that is from a first timing to a second timing. The processor generates, each time the white reference plate is read, the shading correction value based on the plate reading results.