A processing apparatus comprises a correction processor which executes a density unevenness correction process in accordance with properties of each of recording elements included in a recording head of an recoding apparatus, and a convertor which converts the image data, on which the density unevenness correction processing has been executed, into halftone image data, by using a dither matrix, wherein the dither matrix is a dispersive dither matrix, and has characteristics in which when input image data having a uniform tone is converted into binary halftone image data, the same number of dots are present at each of locations in a first direction, in a predetermined range in a second direction, for a tone, among the tones which the input image data can take on, that is subject to the density unevenness correction process.

An image processing apparatus performs quantization processing of first multivalued image data, second multivalued image data, and third multivalued image data using a dither pattern including a plurality of threshold pixels having threshold values respectively determined for quantization, generates first recording data by quantizing the first multivalued image data using a dither pattern having a threshold pixel arrangement satisfying a predetermined condition regarding the number of threshold pixels and a predetermined condition regarding low-frequency components corresponding to a frequency region lower than a predetermined frequency in spatial frequency characteristics corresponding to an arrangement of the threshold pixels, generates second recording data by quantizing the second multivalued image data using the dither pattern having the threshold pixel arrangement, and generates third recording data by quantizing the third multivalued image data using the dither pattern having the threshold pixel arrangement and the second multivalued image data.

An image processing apparatus includes a target value calculation unit configured to calculate a target value to be output in a predetermined region in input image data based on pixel values of pixels included in the region, a distribution order determination unit configured to determine a distribution order of output values for distributing output values corresponding to the target value in the region based on a pixel value of each pixel included in the region and a threshold value in the threshold matrix corresponding to the pixel, and an output value determination unit configured to determine an output value of each pixel included in the region by allocating the target value to at least one pixel included in the region in the distribution order.

An image processing apparatus includes a storage and processing circuitry. The storage is configured to store a dither table in which a plurality of dither patterns are recorded, each of the dither patterns being formed with a halftone dot screen in which an output area ratio that is a proportion of void halftone dots per unit area corresponds to any one of gradation values of image data. The processing circuitry is configured to read a gradation value for each region in image data input for each toner color, decide a dither pattern to be applied to the read gradation value, read out the decided dither pattern from the dither table, and perform dither processing of applying the read dither pattern to the region in the image data.

An image processing apparatus that prints an image includes a preliminary halftone processing unit configured to determine whether a preliminary dot through a dithering method is to be formed, a final halftone processing unit configured to determine whether a dot to be printed through an error diffusion method is to be formed, and a dither result application level control unit configured to control a dither result application level which is a level at which probability that the dot to be printed will be formed is raised with the final halftone processing unit when the preliminary dot is to be formed in the preliminary halftone processing unit. The dither result application level control unit reduces the dither result application level during printing in a case of copying a reflected document or a case where the image data contains many high-frequency components, compared to other instances of printing.

An image processing apparatus includes a target value calculation unit configured to calculate a target value to be output in a predetermined region in input image data based on pixel values of pixels included in the region, a distribution order determination unit configured to determine a distribution order of output values for distributing output values corresponding to the target value in the region based on a pixel value of each pixel included in the region and a threshold value in the threshold matrix corresponding to the pixel, and an output value determination unit configured to determine an output value of each pixel included in the region by allocating the target value to at least one pixel included in the region in the distribution order.

A Raster Image Processing (RIP) module includes an object detection module configured to receive at least one input file, detect objects in the at least one input file and create at least one image comprising a predefined number of stripes along the edges of the detected objects, an edge processing module configured to receive the at least one image and process the at least one image by changing the gray level of each one of the objects' stripes according to an edge processing table; and a dithering module configured to receive the at least one processed image, dither the at least one processed image according to the at least one image's gray levels and output a printing ready file.

A Raster Image Processing (RIP) module includes an object detection module configured to receive at least one input file, detect objects in the at least one input file and create at least one image comprising a predefined number of stripes along the edges of the detected objects, an edge processing module configured to receive the at least one image and process the at least one image by changing the gray level of each one of the objects' stripes according to an edge processing table; and a dithering module configured to receive the at least one processed image, dither the at least one processed image according to the at least one image's gray levels and output a printing ready file.

A white-plate graphic erosion process is performed on print data subjected to a RIP process in the following procedure. First, an erosion candidate region which is a candidate for a region in which a white-plate graphic is eroded is determined. Then, a region to be applied with an ink of a color other than white is determined. Then, an application target region is determined. Then, a region other than a region obtained by an erosion process out of the application target region is determined to be an erosion allowed region. Then, a region included in the colored region and the erosion allowed region out of the erosion candidate region is determined to be an erosion target region. Finally, the values of data of pixels included in the erosion target region among white-plate data are rewritten such that the amount of white ink applied to the pixels is reduced.

An image processing apparatus performs quantization processing of first multivalued image data, second multivalued image data, and third multivalued image data using a dither pattern including a plurality of threshold pixels having threshold values respectively determined for quantization, generates first recording data by quantizing the first multivalued image data using a dither pattern having a threshold pixel arrangement satisfying a predetermined condition regarding the number of threshold pixels and a predetermined condition regarding low-frequency components corresponding to a frequency region lower than a predetermined frequency in spatial frequency characteristics corresponding to an arrangement of the threshold pixels, generates second recording data by quantizing the second multivalued image data using the dither pattern having the threshold pixel arrangement, and generates third recording data by quantizing the third multivalued image data using the dither pattern having the threshold pixel arrangement and the second multivalued image data.