An image forming apparatus includes a printing device, an output value converting unit, and a controller. The output value converting unit is configured to (a) change pixel values of pixels alternatively determined in a primary scanning direction and a secondary scanning direction so as to delete a dot on the pixels in a solid part in a target image and (b) change pixel values of pixels that are alternatively not determined in the primary scanning direction and the secondary scanning direction so as to gain a dot size of the pixels in the solid part. The controller is configured to control the printing device so as to print the solid part with dot sizes corresponding to the pixel values.

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 apparatus includes a moving unit, a first detecting unit, and a second detecting unit. The moving unit moves a calibration plate in the main scanning direction relatively to a reading apparatus. The calibration plate is a plate for calibrating the reading apparatus. The reading apparatus has a reading unit and reading glass. The reading unit is arranged in the main scanning direction. The reading glass is disposed on a reading surface side of the reading unit. The first detecting unit detects an abnormality on the calibration plate from reading results. The reading results are obtained in such a manner that, while the moving unit is controlled to move the calibration plate, the reading unit reads the calibration plate. The second detecting unit detects an abnormality on the reading glass from the reading results.

There is a need to prevent the amount of information about read images from increasing excessively, improve the productivity, and reduce the storage capacity to store read images. There is provided a level setter that sets a level of accuracy for an image inspection process. An inspection image data generator generates inspection image data by using a resolution or a gradation setting corresponding to a level set by the level setter. A comparison image data generator generates comparison image data by using a resolution or a gradation setting corresponding to a level set by the level setter. Lowering a level set by the level setter decreases the amount of the inspection image data and the comparison image data.

An image forming apparatus includes a printing device, an output value converting unit, and a controller. The output value converting unit is configured to (a) change pixel values of pixels alternatively determined in a primary scanning direction and a secondary scanning direction so as to delete a dot on the pixels in a solid part in a target image and (b) change pixel values of pixels that are alternatively not determined in the primary scanning direction and the secondary scanning direction so as to gain a dot size of the pixels in the solid part. The controller is configured to control the printing device so as to print the solid part with dot sizes corresponding to the pixel values.

A correction method for an image forming apparatus including a light source, a photosensitive member configured to rotate in a first direction, and a deflecting unit configured to deflect light beams emitted from the light source in a second direction orthogonal to the first direction to form scanning lines, the correction method including: a first correction step of correcting sparseness and denseness of density by moving a predetermined pixel in the first direction to output a pixel value of the predetermined pixel; and a second correction step of correcting the pixel value of the predetermined pixel by, when the pixel value of the predetermined pixel moved in the second direction is equal to or less than a predetermined value, adding the pixel value to a pixel value of a subsequent pixel of the predetermined pixel in the second direction without outputting the pixel value of the predetermined pixel.

A light source drive control device includes: an image data generating part that generates line-thinned image data having been subjected to line thinning processing for thinning an edge pixel in image data by a first pixel width; an intensity information generating part that generates intensity information including a first intensity at which a pixel not included in a set second pixel width of an edge in the line-thinned image data is exposed and a second intensity at which a pixel included in the second pixel width is exposed and which is higher than the first intensity; and a light source driving part that drives a light source based on a light source modulation signal generated according to the line-thinned image data and a drive current data switched based on a drive current switching signal generated based on the intensity information.

An image reading apparatus can inhibit image disturbance and density unevenness. The image reading apparatus includes a first conveyance roller pair, a back side image reading unit, a second conveyance roller pair, a front side image reading unit, a third conveyance roller pair, and a control unit. The control unit compares the image data read by the back side image reading unit and the image data read by the front side image reading unit to calculate a relative magnification variation there between, corrects the reading time of the front side image reading unit for each line based on the calculated relative magnification variation, and performs, in accordance with correction of the reading time, image correction of the image data of the front side image reading unit which has been corrected with respect to the reading time.

An image reading apparatus includes a reading circuit, a white reference member, a control circuit, a memory circuit, and a processing circuit. The control circuit controls the reading circuit to: cause a light source to irradiate the white reference member with lights of a plurality of colors and cause a light receiving unit to receive the reflected lights. The processing circuit performs a process to identify abnormal data included in white reference data stored in the memory circuit. The processing circuit identifies information on the abnormal data in a light of an abnormal-data detected color among the plurality of colors. The processing circuit identifies the abnormal data in lights of other colors excluding the abnormal-data detected color among the plurality of colors based on the information on the abnormal data. The information is identified for the light of the abnormal-data detected color.

A read image processing apparatus is provided for processing a read image read by line image sensors arranged such that one end parts of which adjacent to each other are overlapped in a sub-scanning direction. The read image processing apparatus includes a density variation detector, a seam processor, and a line image generator. The density variation detector detects whether a density variation occurs for not less than a predetermined number of times or not in each of a plurality of regions in a seam-read image. The seam processor generates a seam image by synthesizing the seam-read images read by the line image sensors adjacent to each other in accordance with a detection result made by the density variation detector. The line image generator generates a read image corresponding to one line based on read images read by the line image sensors and the seam image generated by the seam processor.