An image processing apparatus includes a processing unit that converts first input image data for a first region and second input image data for a second region to reduce a difference between first region recorded image density and second region recorded image density, and generates dot position data of a dot to be generated in each of the first and second regions based on the dot data after the conversion processing. The acquisition unit acquires edge information indicating a first object pixel edge of an image pixel for the first region and a second object pixel edge of an image pixel for the second region. Based on the acquired edge information, conversion and generation processing are performed in such a manner that a color signal of an edge pixel is increased/reduced to a degree lower than a degree to which a color signal of a non-edge object pixel is increased/reduced.

A determination unit determines whether a difference between a maximum value and a minimum value of pixel values of a plurality of pixels in a region of interest in N-gradation multi-valued data, where N≥4, representing the pixel values of the plurality of pixels is less than a determination threshold value. A generation unit generates M-gradation quantization data represented by an M-gradation quantization value, where 3≤M<N, based on the N-gradation multi-valued data and the determination. In a case where the determination unit determines that the difference is less than the determination threshold value, the generation unit generates the M-gradation quantization data so that each of the plurality of pixels corresponding to the region has a value that is one of two consecutive values of the M-gradation quantization values in the generated M-gradation quantization data.

An information processing apparatus includes circuitry configured to recognize a character in an original image by character recognition, to generate a font, calculate a certainty factor of the character recognition, determine a color of the font based on the certainty factor by a first processing method, and determine a replacement color by a second processing method based on the certainty factor, and convert the original image into an editable electronic document including the font and an image in which the character pixel has the replacement color. The replacement color is a color to which a color of a character pixel of the recognized character is replaced.

Certain examples described herein relate to color spaces. In some cases, data representing a set of color values is obtained. Each color value has, for each of first, second and third axes defining a three-dimensional color space, a respective coordinate value. In some cases, for each of the set of color values, the coordinate value for the first and/or second axis is transformed dependent on the coordinate value for the third axis, to generate data representing a transformed set of color values. A set of output color values in an output color space is derived using the generated data. Output data associating the set of output color values in the output color space with a set of further color values in a further color space is generated.

An image forming apparatus includes: an image forming unit configured to form a reference image, and a plurality of test images; a conveying unit configured to convey the sheet; a reading unit configured to read the sheet, and output read data, the reading unit including a plurality of light-receiving elements disposed along a direction orthogonal to a conveyance direction of the sheet; and a controller configured to: determine a direction in which the plurality of test images are disposed based on read data related to the reference image; determine test image read data related to test image regions corresponding to each of the plurality of test images from the read data based on the direction; and control a density of an image to be formed by the image forming unit based on the test image read data.

A printing apparatus includes a first memory, a second memory, an input circuit that alternately inputting second reference data and third reference data different from each other to the second memory, a processing circuit that performs first color processing with reference to first reference data in the first memory on print data, second color processing with reference to the second reference data in the second memory on the print data, and third color processing with reference to the third reference data in the second memory to the print data, and a printing mechanism that performs printing.

In a printing apparatus configured to print an image by bidirectional multipass printing while using multiple print element rows that apply color material of the same color, a high-quality image suppressed in hue unevenness and density unevenness is printed. To this end, the printing apparatus forms first and second dot patterns on a print medium in an overlapping manner. In the first dot pattern, dot arrays in which first dot groups are arranged at an interval B1 are arranged in a nozzle arrangement direction while being shifted from each other by C1 in a scanning direction of a print head. In the second dot pattern, dot arrays in which the first dot groups are arranged at the interval B1 are arranged in a nozzle arrangement direction while being shifted from each other by C2 in the scanning direction of the print head. Here, values of C1 and C2 are different.

An information processing apparatus includes circuitry configured to recognize a character in an original image by character recognition, to generate a font, calculate a certainty factor of the character recognition, determine a color of the font based on the certainty factor by a first processing method, and determine a replacement color by a second processing method based on the certainty factor, and convert the original image into an editable electronic document including the font and an image in which the character pixel has the replacement color. The replacement color is a color to which a color of a character pixel of the recognized character is replaced.

An image processing apparatus includes a halftone processing unit and a multi-level gradation processing unit. The halftone processing unit is configured to perform a halftone process for a target image and generate a binary image corresponding to the target image. The multi-level gradation processing unit is configured to (a) set a target pixel as a dot pixel in the binary image, (b) determine whether a dot exists on plural first periphery pixels with a predetermined first distance from the target pixel and plural second periphery pixels with a predetermined second distance from the target pixel or not, (c) derive a gradation level of the target pixel among predetermined three or more gradation levels on the basis of a number of dots on the plural first periphery pixels and a number of dots on the plural second periphery pixels and thereby generate a multi-level gradation image.

A method of screening a continuous-tone image is configured to produce an output image to be printed on a surface. The continuous-tone image comprises a plurality of pixels having respective corresponding intended print locations. The method includes selecting a first sequence comprising a subset of the plurality of intended print locations, the first sequence being selected based on properties of the plurality of intended print locations. For each intended print location in the first sequence, the method also includes identifying the corresponding pixel in the continuous-tone image to obtain a second sequence for an error diffusion process comprising the identified corresponding pixels in the continuous-tone image.