A head unit includes heads arranged in a body. Each head includes a nozzle row arranged along a first direction. The heads are arranged along a second direction intersecting with the first direction. Two or more heads that include a nozzle row corresponding to a first color, are provided in each of a first region and a second region. A color corresponding to the nozzle row at an nth position from a first side is the same as a color corresponding to the nozzle row at an nth position from a second side, n being a positive integer, the first side being one side of the body in the second direction and the second side being another side of the body in the second direction.

A test pattern formation method includes preparing a first pattern including a plurality of dot rows that are separated, and a second pattern including a plurality of regions having a width greater than a width of the plurality of dot rows and provided spaced apart by a plurality of gaps greater than or equal to the width of the plurality of dot rows. At least a portion of the first pattern and at least a portion of the second pattern are in positions overlapping each other. Given a largest overlap between one of the plurality of dot rows and one of the plurality of gaps as a reference, the other dot rows of the plurality of dot rows and the plurality of regions having a wide width overlap and are deviated from each other incrementally by a respective distance corresponding to a landing deviation amount.

In an image processing device, a controller is configured to perform: selecting; generating; and outputting. The selecting selects a target partial image one by one from a plurality of partial images. The target partial image is represented by target partial image data. The generating generates partial print data for a partial print by executing an image process on the target partial image data. The partial print forms the target partial image while moving a print head in a printing direction. The partial print forms the target partial image while moving a print head in a printing direction. The image process includes a color conversion process. The color conversion process is executed on the target partial image data using one of a first profile and a second profile selected in accordance with the printing direction set for the partial print. The outputting outputs the partial print data to the printer.

In an image processing apparatus, a processor sets a target printing method for printing a target image to one of a bidirectional printing method and a unidirectional printing method. In a case where the bidirectional printing method is set as the target printing method: the processor executes both a first generation process and a second generation process. The first generation process generates first partial print data by converting a set of partial image data using a first color conversion profile. The second generation process generates second partial print data by converting another set of partial image data using a second color conversion profile. In a case where the unidirectional printing method is set as the target printing method, the processor executes a third generation process generating third partial print data by converting a set of partial image data using a third color conversion profile.

A printing method and a printing apparatus are provided. After ink droplets of a photocurable ink are landed on a print medium, a scan of applying a light to cure the ink droplets to form dots is performed alternately in a forward direction and a backward direction with respect to a predetermined unit region, and a time from landing to curing of the ink droplets onto the print medium differs between the forward direction and the backward direction. The printing method includes: providing the ink droplets that include: a large dot having a large amount of ink per droplet, and a small dot having a smaller amount of ink per droplet than that of the large dot; and controlling ejection of the ink droplets, such that number of passes when forming the large dot is greater than number of passes when forming the small dot, when forming a print image.

An inkjet printer comprises a transport mechanism (120) for transporting a substrate along a first axis, a print engine (160) comprising at least two inkjet print bars (165.1 . . . 8) arranged along the first axis, and a controller for controlling the ejection of ink by the at least two inkjet print bars. It further comprises at least two first encoders for the determination of at least two first positions of substrate locations along the first axis and a compensation module for processing the at least two determined first positions to generate at least one first individual compensation parameter for each of the at least two inkjet print bars (165.1 . . . 8). The first compensation parameters are transmitted to the controller to influence the ejection of ink in such a way that effects due to variations of the at least two first positions of the substrate along the first axis are compensated. The effects of positioning errors that may affect different print bars (165.1 . . . 8) arranged along the longitudinal axis of the print engine (160) differently may be compensated using the encoders, individually for the different print bars (165.1 . . . 8).

In a state where a distance from an ejection port surface of an ejection head to a predetermined position corresponds to a first distance, a period detection unit detects a first period from when ejection of a droplet from an ejection port is started until when a droplet detection unit detects the droplet, and in a state where the distance from the ejection port surface of the ejection head to the predetermined position is changed to a second distance by a change unit, the period detection unit detects a second period from when ejection of a droplet from the ejection port is started until when the droplet detection unit detects the droplet, the second distance being different from the first distance. A calculation unit calculates an ejection speed of the droplet, based on the first distance, the second distance, the first period, and the second period.

Wherein, in the first dither mask, when the first space is cut by the first plane, a plurality of threshold values in the first plane has a blue noise characteristic in the spatial frequency domain, and when the first space is cut by a second plane extending in a direction different from that of the first plane, a plurality of threshold values in the second plane has a blue noise characteristic in the spatial frequency domain.

In a color printing environment, functions for printing color management are dissociated. An abstraction layer is also provided to facilitate setting and evaluation of all factors relating to color print and prediction.

An image processing apparatus processes image data to be used in a printing apparatus configured to perform forward and backward scan printing by using a print head in which nozzle arrays corresponding to multiple colors are aligned. The image processing apparatus includes: a setting unit configured to set a first control parameter in a case where image data to be processed does not include a line portion and to set a second control parameter in a case where the image data to be processed includes a line portion, the second parameter being different from the first control parameter; and a processing unit configured to perform, for the image data to be processed, processing to suppress a difference between a color printed in a forward scan and a color printed in a backward scan based on the control parameter set by the setting unit.