An image forming apparatus includes at least one processor that is configured to generate second image data corresponding to each of a plurality of light emitting elements based on first image data, the second image data indicating whether to cause each of the plurality of light emitting elements to emit light, and based on correction information, change the first image data indicating that the light emitting elements are to emit light to the second image data indicating that the light emitting elements are not to emit light. A circuit unit is configured to supply a current to each of the plurality of light emitting elements based on the second image data.

An image processing device includes a dithering circuit, a gradation correction pattern generating circuit, and a gradation correction pattern correcting circuit. The dithering circuit performs a dithering process on image data to generate dithered image data. The gradation correction pattern generating circuit sets, in multi-valued data, gradation information of each of pixels of the generated dithered image data, and generates a gradation correction pattern imitating the dithered image data. The gradation correction pattern correcting circuit performs pattern matching on the generated gradation correction pattern, and corrects the generated gradation correction pattern in accordance with a result of the pattern matching.

An image processing apparatus includes: an image determining unit configured to determine a gradation value for each predetermined range in input image data; and a screen generator configured to arrange dot images around a plurality of growth centers in a halftone dot screen to form respective dot blocks if an input area rate indicating a ratio of black to white in dot images at the gradation value is smaller than a value at which an image defect occurs, and form bridges to connect adjacent dot blocks during a smallest gradation number if distances between the adjacent dot blocks decrease to a predetermined value or less along with growth of the dot blocks, to form a void halftone dot image.

An image forming apparatus includes: at least one processor that is configured to generate second image data corresponding to each of a plurality of light emitting elements based on first image data, the second image data indicating whether to cause each of the plurality of light emitting elements to emit light, and based on correction information, change the first image data indicating that the light emitting elements are to emit light, to the second image data indicating that the light emitting elements are not to emit light, and the circuit unit configured to supply a current to each of the plurality of light emitting elements based on the second image data.

An image forming apparatus includes a conversion unit configured to convert image data based on a conversion condition which corresponds to a type of halftone processing; an image processing unit configured to execute the halftone processing on the image data converted by the conversion unit, wherein the halftone processing includes first halftoning and second halftoning which is different from the first halftoning; and an image forming unit including a photoreceptor and an exposure unit configured to expose, based on the image data on which the halftone processing is executed by the image processing unit, the photoreceptor with light to form an electrostatic latent image on the photoreceptor.

An electrophotographic image forming apparatus, which utilizes a line head in which a plurality of light-emitting elements is arranged as a light source, includes at least one controller having at least one processor and at least one memory. The controller is configured to obtain print data to perform printing, perform halftone processing for the obtained print data, generate a plurality of pieces of correction information for correcting variations of light amount on a photosensitive body by light radiated from the plurality of light-emitting elements, and correct the print data for which the halftone processing has been performed by using the correction information. The correction information includes various profiles for correcting the variations of light amount.

An image processing apparatus includes: an image determining unit configured to determine a gradation value for each predetermined range in input image data; and a screen generator configured to arrange dot images around a plurality of growth centers in a halftone dot screen to form respective dot blocks if an input area rate indicating a ratio of black to white in dot images at the gradation value is smaller than a value at which an image defect occurs, and form bridges to connect adjacent dot blocks during a smallest gradation number if distances between the adjacent dot blocks decrease to a predetermined value or less along with growth of the dot blocks, to form a void halftone dot image.

An image forming apparatus includes a photosensitive member, an exposing unit scanning the photosensitive member with a laser, a generating unit generating a clock signal, a first correcting unit correcting a frequency of the clock signal for each position in a main scanning direction, a developing unit, a driving unit, a second correcting unit correcting an image date by a correction coefficient depending on the position in the main scanning direction, and a modulating unit modulating the image date corrected by the second correcting unit into the driving signal. The correction coefficient increases as it goes toward an end from a center in the main scanning direction and includes an inflection point where an inclination, which is an increase amount of the correction coefficient to a unit increase amount of the position, is changed. The inflection point is positioned near the end in the main scanning direction.

An exposure head includes a substrate on which light sources are mounted, and a condensing optical system. A memory stores a profile indicating correction gains for exposure amounts. A sensor detects a temperature. A processor acquires a correction gain that corresponds to a position of a light source that reached an exposure timing, corrects, for each of the light sources, an exposure amount of the light source with the correction gain corresponding to the position of the light source, and adjusts, for each of the light sources, a reference position of the corresponding correction gain in the profile in accordance with the temperature detected by the sensor.

An image forming apparatus includes at least one processor that is configured to generate second image data corresponding to each of a plurality of light emitting elements based on first image data, the second image data indicating whether to cause each of the plurality of light emitting elements to emit light, and based on correction information, change the first image data indicating that the light emitting elements are to emit light to the second image data indicating that the light emitting elements are not to emit light. A circuit unit is configured to supply a current to each of the plurality of light emitting elements based on the second image data.