A printing system is disclosed. The printing system includes a halftone calibration module to receive one or more un-calibrated halftones, transform un-calibrated threshold values in the one or more un-calibrated halftones via an inverse transfer function to generate calibrated halftone threshold values and generate one or more calibrated halftones based on the calibrated halftone threshold values.

Multi-value image data is sampled for each predetermined pixel range to generate tone information of the pixel range. The generated tone information is stored in a storage unit. Attribute information representing the attribute of a pixel is generated from the multi-value image data, and the generated attribute information is stored in the storage unit. Halftone processing is performed on the multi-value image data based on the tone information and attribute information stored in the storage unit.

Provided is an image data setting apparatus capable of setting image data related to a foil forming image. The image data setting apparatus includes a hardware processor determining whether a setting for the foil forming image is included in a printing job related to the image data, in which the hardware processor changes a halftone dot setting of the image data, according to a determination result.

With this invention, color shifting correction is performed first based on shifting amount information indicating a shifting amount with respect to the scanning direction on an image carrier of each image forming unit, and halftone processing is then performed, thus suppressing generation of moiré due to the color shifting correction, and forming a high-quality image. To this end, an image forming engine has color shifting amount storage units C, M, Y, and K (black) which store actual shifting amounts with respect to ideal scan directions on image carriers C, M, Y, and K in image forming units C, M, Y, and K. Color shifting correction amount arithmetic units C, M, Y, and K calculate color shifting correction amounts for respective color components on the basis of the stored color shifting amounts. Color shifting correction units C, M, Y, and K perform color shifting correction by converting coordinates upon reading out image data from bitmap memories C, M, Y, and K on the basis of the calculated color shifting correction amounts, and then perform tone correction. Data after tone correction undergo halftone processing by halftone processors. C, M, Y, and K. PWM processors C, M, Y, and K generate PWM signals for scanning, and output them to exposure units C, M, Y, and K of the respective image forming units.

An image processing apparatus is equipped with: an image data receiving unit that receives image data; and a print data generating unit that generates multiple value data as print data by performing a halftone process on the image data and converting the image data into at least three values. The print data generating unit administers a halftone process that includes a density fluctuation suppressing process that results in the print data always including a zero value except for a case in which all of the pixels that constitute the image data are converted into a maximum value.

A raster image processor (RIP) for digital binary halftoning a continuous tone image (CT) by a threshold tile (TT) into a halftone raster image (RT) for a printing device capable of printing on a plurality of substrates (S.sub.1, S.sub.2, . . . , S.sub.M); wherein said processor comprises an input field in which information regarding a substrate is to be used; a memory having stored thereon a plurality of threshold tiles (TT.sub.1, TT.sub.2, . . . , TT.sub.N) for generating regularly tiled halftone dots; and a threshold selector which is capable to select said threshold tile (TT) of said plurality of threshold tiles (TT.sub.1, TT.sub.2, . . . , TT.sub.N) based on information supplied to the input field.

Provided is a printing method for performing printing using a serial printer. In printing of a print image including a line image, the printing method includes a raster line forming step of forming each of raster lines configuring the image, by a plurality of pass operations. In the formation of each of the raster lines, when printing of a region corresponding to edge pixels of the line image by a first pass operation, which is one of the plurality of pass operations, is first printing, and printing of the region corresponding to the edge pixels by a second pass operation that is different from the first pass operation, of the plurality of pass operations, is second printing, a brightness of the printing by the second printing is higher than a brightness of the printing by the first printing.

An image processing method configured to process an image constituted by a plurality of pixels arranged two-dimensionally includes the steps of dividing the image into a plurality of blocks, and comparing image data of the pixel included in a first block as one of the blocks divided into with a first threshold value, and converting the image data into first dot data representing whether to form a dot using an error diffusion method. Further, processing of comparing image data of the pixel included in a second block as a block adjacent to the first block with a second threshold value prepared in advance, and converting the image data into second dot data representing whether to form a dot using an error diffusion method is performed independently of a first processing section. On this occasion, the first threshold value and the second threshold value include variable components periodically varying along two-dimensional arrangement directions of the pixels, respectively, and the variable components are provided with the same phase at a junction between the first block and the second block.

A halftone raster image suitable for rendering a continuous-tone image includes a plurality of spiral dots. The spiral dots include image pixels arranged as a first arc or as a plurality of arcs which together represent a first spiral, and non-image pixels arranged as a second arc or as a plurality of arcs which together represent a second spiral. The spiral dots enable a controlled spreading of the ink within the dot, resulting in a higher image quality, ink saving, and faster drying.

There are provided a printing system, a method of generating a halftone processing rule, a method of acquiring a characteristic parameter, image processing device and method, a halftone processing rule, a halftone image, a method of manufacturing a printed material, an ink jet printing system, and a program which are capable of reducing an operation load of a user and acquiring a halftone processing rule appropriate for the printing system. A characteristic parameter acquisition chart including a pattern for acquiring characteristic parameters related to characteristics of the printing system is output, and the output characteristic parameter acquisition chart is read by image reading means. The characteristic parameters are acquired by analyzing the read image of the characteristic parameter acquisition chart, and halftone processing rules that define the processing contents of halftone processes used in the printing system are generated based on the acquired characteristic parameters.