In some examples, dynamic threshold based error diffusion may include determining whether a pixel associated with a pattern to be printed includes a lighter tone or a darker tone compared to an adjacent pixel. In response to a determination that the pixel associated with the pattern to be printed includes the lighter tone or the darker tone compared to the adjacent pixel, a firing threshold may be respectively increased or decreased to respectively decrease or increase a likelihood of printing of the pattern.

In some examples, dynamic threshold based error diffusion may include determining whether a pixel associated with a pattern to be printed includes a lighter tone or a darker tone compared to an adjacent pixel. In response to a determination that the pixel associated with the pattern to be printed includes the lighter tone or the darker tone compared to the adjacent pixel, a firing threshold may be respectively increased or decreased to respectively decrease or increase a likelihood of printing of the pattern.

A three-dimensional image forming system according to an embodiment of the present invention is a system that expands the front side of a thermally expandable sheet formed by laminating a thermally expanding layer on a base material and forms irregularities in a desired area, the system includes a print data density adjusting unit that adjusts, in print data for printing, on the back side of the thermally expandable sheet, a grayscale image for expanding the thermally expandable sheet to a surface height according to a density, the density of an outline part obtained by setting a region from a boundary between adjacent two regions having different densities in the grayscale image to a predetermined distance as the outline part in at least either of the two regions having different densities such that steep steps are formed on the front side of the thermally expandable sheet at the boundary.

Provided are a density unevenness correction data creation method, a density unevenness correction data creation apparatus, a printing system, a program, a test chart, and a test chart data creation apparatus in which density unevenness correction with high accuracy is implemented. A captured image of a test chart including a density step pattern, an alignment mark, and a line mark is acquired, and in a case of acquiring correspondence relationship information between a theoretical position and an imaging position from the captured image, a rough correspondence relationship is acquired by using positional information of the alignment mark, a detailed correspondence relationship is acquired by using positional information of the line mark estimated by using the rough correspondence relationship, and density unevenness correction data is created by estimating a density value of each position of the density step pattern by using the detailed correspondence relationship.

An image analyzer includes an in-use ink information determination section that determines an ink type to be used for printing and an ink quantity to be used for printing for the ink type as in-use ink information by using image data in accordance with conditions set in advance, a printed image quality information acquisition section that acquires at least one item of printed image quality information on image quality specified in advance and provided when the image data is printed by using the determined in-use ink information, and a display section that displays at least one of the in-use ink information and the printed image quality information.

An image processing apparatus that generates data for setting different colors for a projected portion and a recessed portion of an unevenness on a surface of a recording medium by recording a colored printing material on at least the projected portion of the unevenness includes a first acquisition unit configured to acquire recording amount data representing a recording amount of the colored printing material, and a halftoning unit configured to perform first halftoning on the recording amount data to arrange a larger number of dots of the colored printing material to be recorded on the projected portion of the unevenness at a center of the projected portion than at edges of the projected portion.

A recording method includes: ejecting colored ink compositions that include a cyan ink composition, a magenta ink composition, a yellow ink composition, and a special color ink composition with a hue angle different from hue angles of the respective ink compositions from an ink jet head and causing the ink compositions to adhere to a recording medium; and causing a processing solution containing a coagulant for coagulating constituents of the colored ink compositions to adhere to the recording medium, the causing of the ink compositions to adhere is performed by performing scanning, in which the colored ink compositions are ejected while a relative position of the ink jet head with respect to the recording medium is changed in a scanning direction, a plurality of times, and a maximum distance of scanning performed once in the causing of the ink compositions to adhere is equal to or greater than 50 cm.

A recording method includes: ejecting colored ink compositions that include a light colored ink composition and a dark colored ink composition that belong to a same color system and have different color density from an ink jet head and causing the ink compositions to adhere to a recording medium; and causing a processing solution that contains a coagulant for coagulating constituents of the colored ink compositions to adhere to the recording medium, the causing of the ink compositions to adhere is performed by performing scanning, in which the colored ink compositions are ejected while a relative position of the ink jet head with respect to the recording medium is changed in a scanning direction, a plurality of times, and a width in the scanning direction of the recording medium is equal to or greater than 50 cm.

A method for correcting an image includes: moving first and second ink jet heads and a medium relative to each other, each of the first and second ink jet heads including nozzles and drive elements corresponding to the nozzles respectively; discharging ink droplets from the nozzles of the first and second ink jet heads, by connecting each of the drive elements to one of power supply circuits and by applying voltage to each of the drive elements, the power supply circuits having different output voltage values each other; determining a density difference between a first image region and a second image region; and switching the voltage to be applied to first drive elements to a first voltage by switching the power supply circuits to be connected to the first drive elements based on the density difference.

An image processing apparatus repeats an ejection process for ejecting color materials by moving a print head in one of a forward direction and a reverse direction in a main scanning direction, and a moving process for moving a print medium in a sub-scanning direction. In a case where an L-th band image satisfies both of a first color condition and a second color condition, a direction of the ejection process is determined to be the same direction as the direction of moving of the print head in the ejection process for another band image including a predetermined number or more of pixels. Where the L-th band image does not satisfy at least one of the first color condition and the second color condition, the direction process of the ejection process is determined to be an opposite direction to moving of the print head in an (L1)-th ejection process.