An inkjet printer forms ink dots of a first ink and ink dots of a second ink on a recording medium. The inkjet printer performs first screen processing on image data of the second ink to generate a first dot group including the ink dots of the second ink, and performs second screen processing on image data of the second ink to generate a second dot group including the ink dots of the second ink. The inkjet printer forms a first printing layer, on the recording medium, of the ink dots of the first ink and the ink dots of the first dot group, and forms a second printing layer of the ink dots of the second ink, above or below the first printing layer.

An image processing apparatus includes a multi-gradation-level dither processing unit and a screen processing unit. The multi-gradation-level dither processing unit performs a multi-gradation-level dither process for a target image. The screen processing unit performs an FM screen process for the target image for which the multi-gradation-level dither process has been performed. Further, in the multi-gradation-level dither process, the multi-gradation-level dither processing unit selects each pixel in the target image as a target pixel in turn; using a conversion characteristic corresponding to each local pixel position group in a unit matrix, converts a pixel value of the target pixel to one of: a minimum gradation level, a maximum gradation level and an intermediate gradation level corresponding to the pixel value of the target pixel; and sets a pixel value of each pixel in the unit matrix as a pixel value obtained with the conversion characteristic.

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 forming method being configured to execute halftone processing using a dithering matrix on input image, output a halftone image, perform correction on the halftone image to shift a pixel at a correction position, and generate an image with a converted lower resolution based on the corrected image, wherein the matrix includes a plural sub-matrices, wherein an arrangement of a threshold in a first sub-matrix is configured to form a first halftone dot having a first line shape for an input image with a predetermined density, wherein an arrangement of a threshold in a second sub-matrix is configured to form a second halftone dot with the same angle as the first line shape and having a center position different from the first halftone dot for the input image with the predetermined density, and wherein the first and second halftone dot form a line shape with a predetermined screen angle.

In an example, an apparatus is described that includes a color conversion module an a visual noise module. The color conversion module converts page description language describing an image into rasterized image data. The visual noise module then recalculates pixel values in an area of flat tint detected in the rasterized image data to introduce visual noise in the area of flat tint.

The present invention provides an image processing apparatus which employs a dither method capable of printing a thin line of desired density without any break irrespective of printing conditions. The first threshold changing unit changes part of threshold values in a threshold matrix to generate a first threshold matrix so as to increase the number of dots to be printed in a specific pixel area. The second threshold changing unit changes part of threshold values in the threshold matrix to generate a second threshold matrix such that the number of dots to be printed in a specific pixel area is smaller than the case of changing a threshold value by the first threshold changing unit. A determining unit determines whether a threshold value in the threshold matrix is to be changed by the first threshold changing unit or by the second threshold changing unit.

The present disclosure aims to provide a high quality image without conspicuous graininess and density unevenness. An embodiment of the present invention is an apparatus for printing a plurality of dot patterns on a printing medium, the dot patterns being formed by substantially same color and substantially same dot diameter, the apparatus including: a first creation unit configured to create, based on a first tone value, a first dot pattern and a second dot pattern printed and superimposed on the first dot pattern; and a second creation unit configured to create, based on a second tone value larger than the first tone value, a third dot pattern having an equal or larger number of dots compared to the first dot pattern and a fourth dot pattern printed and superimposed on the third dot pattern and having an equal or larger number of dots compared to the second dot pattern.

An information processing apparatus, in accordance with rising density in an extreme density range, determines a threshold for setting each pixel of the threshold matrix so as to consecutively grow an isolated dot corresponding to a halftone dot in a low density range to a first dot size for each submatrix; sets, when the size of isolated dots in a predetermined number of submatrices is grown to the first dot size, an intermediate position between the isolated dots in the predetermined number of submatrices; and determines, for each of one or more submatrices including a set intermediate position, a threshold to set for each pixel of the threshold matrix so that an isolated dot is consecutively grown until a second dot size smaller than the first dot size.

A recording control apparatus for recording a captured image obtains an image to be recorded and analysis information based on a distance to an object in each portion of the image. When causing a recording control unit to execute recording of the image, the recording control apparatus selects, on the basis of a value of each pixel of the image and the analysis information, a dot layout pattern that is used to record each pixel of the image and that indicates a layout of recorded dots included in dots constituting the pixel.

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.