To generate a dot pattern whose deterioration of a feeling of granularity, density unevenness, and streaks are unlikely to be recognized visually by more effectively suppressing a change of an overlap of ink droplets on a printing medium. Halftone image data representing a dot pattern of each of two or more kinds of dot different in density reproduction is acquired. Then, in a case where there is a possibility that the contact state between dots changes due to a landed-dot shift of ink in a plurality of specific dots on a condition that dots are formed in accordance with a dot pattern in the halftone image data, the plurality of specific dots is replaced with dots of another kind whose number is less than or equal to that of the plurality of specific dots.

An image processing method for generating printing data includes correcting, in accordance with a degree of reduction in a dot coverage below a predetermined dot coverage in a region that undergoes printing in an overlapped manner by a first nozzle group and a second nozzle group, at least either of a first sharing ratio for the first nozzle group sharing positions of dots to be formed in an overlapping image region and a second sharing ratio for the second nozzle group sharing positions of dots to be formed to allow a total ratio of the first sharing ratio and the second sharing ratio to exceed 100%, and correcting a color conversion table based on the first sharing ratio and the second sharing ratio, after the correcting of at least either of the first sharing ratio and the second sharing ratio.

An ink printing process employs per-nozzle droplet volume measurement and processing software that plans droplet combinations to reach specific aggregate ink fills per target region, guaranteeing compliance with minimum and maximum ink fills set by specification. In various embodiments, different droplet combinations are produced through different printhead/substrate scan offsets, offsets between printheads, the use of different nozzle drive waveforms, and/or other techniques. These combinations can be based on repeated, rapid droplet measurements that develop understandings for each nozzle of means and spreads for expected droplet volume, velocity and trajectory, with combinations of droplets being planned based on these statistical parameters. Optionally, random fill variation can be introduced so as to mitigate Mura effects in a finished display device. The disclosed techniques have many possible applications.

A method for carrying out a printing operation on an inkjet printing machine compensates for failed printing nozzles by using a computer. After a screening process in which a halftone image is created for an image to be printed, failed printing nozzles are compensated for by increased ink application from neighboring printing nozzles by precalculating at least one corrective halftone image for the adjacent printing nozzles by using the computer, replacing the halftone image created in the screening process by the corrective halftone image in the at least one column of the neighboring printing nozzles, and carrying out the printing operation on the inkjet printing machine using the corrected halftone.

A printing method includes a step of forming a first image by ejecting a pretreatment liquid, and a step of forming a second image on the first image by ejecting a colored ink onto the first image. Here, the first image is allowed to include an extra portion by which the edge of the first image exists on the outside of the edge of the second image. Further, an amount of the ejection of the pretreatment liquid onto the extra portion per area at a position on the extra portion is allowed to be decreased further as the position is located further toward the outside from the edge of the second image.

A recording head has two or more first nozzle rows from which an ink droplet of a first color is discharged, two or more second nozzle rows from which an ink droplet of a second color is discharged, and two or more third nozzle rows from which an ink droplet of a third color is discharged. In a plurality of nozzle rows from which an ink droplet is discharged on the same line along the relative movement direction, a distance between the first nozzle row and the second nozzle row in the relative movement direction is fixed, and a plurality of distances are present regarding a distance between the first nozzle row and the third nozzle row in the relative movement direction. Concerning an amount-of-ink upper limit that is an upper limit of an amount of ink that is dischargeable per unit area of the print substrate, first printing in which an amount-of-ink upper limit for a combination of the first nozzle row and the third nozzle row is smaller than an amount-of-ink upper limit for a combination of the first nozzle row and the second nozzle row is performed.

In a method for automatic adaptation of a quantity of a coating substance, a coating substance is inkjet printed to a printing region of the recording medium; a first color is over printed across a width of the printing region of the recording medium and atop the coating substance; a print image of a second color is over printed atop the first color; the printing region having been printed to is sensory recorded; a local bleeding behavior of the first and the second colors is analyzed based on the sensory recording; and a printed quantity of the coating substance is locally adapted, based on the analysis of the local bleeding behavior, in segments of the printing region that are affected by bleeding.

Density of each pixel is specified from a test pattern for measurement of density distribution, a density profile indicating distribution of the specified density for each pixel is acquired, and a pixel region including a nozzle of interest having a certain density difference or more from surrounding pixels and pixels on both sides thereof is extracted as a nozzle region of interest from the acquired density profile. Filters B to E, other than a filter A to be applied for density smoothing processing of pixels that do not belong to the nozzle region of interest, are applied for the density smoothing processing of the pixels in the nozzle region of interest, to generate a profile of a density correction value for eliminating a density difference between respective pixels based on the density profile after the smoothing processing.

Provided are an image recording apparatus, a dither mask, and an image recording method capable of reducing occurrence of concentration unevenness without decrease in productivity. In an image recording apparatus that repeats a main scan operation of relatively moving a recording head having a nozzle row with respect to a recording medium in a main scan direction to perform recording and a sub scan operation of relatively moving the recording medium with respect to the recording head in a sub scan direction, a nozzle jetting rate of each nozzle is controlled by a dither mask. The dither mask is subjected to threshold setting so that a sum of a sum of nozzle jetting rates of corresponding nozzles of respective nozzle groups used in recording a first half scan for recording each scan band and a sum of nozzle jetting rates of corresponding nozzles of respective nozzle groups used in recording a second half scan becomes a specific value that is in a defined allowable range, with respect to at least a part of a recording duty range.

In an imaging method an image or multiple images, an ink specification and substrate or substrates for imaging are selected. A central computing device (CCD) determines a volume of ink required to form the images and communicates with a plurality of printers that are geographically remote from the CCD. Each of the plurality of printers communicates to the CCD an ink specification available at the printer, a volume of ink available and optionally substrates that are available at the printer location. The CCD selects a printer or printers from the plurality of printers to fulfill the print job considering the geographic location of the printer(s), the ink specification available to the printer, and the volume of ink available at the printer. The CCD provides to the printer information and specifications which may include an image specification, an ink specification, a waveform specification and a substrate specification.