An image processing apparatus including a controller for controlling a print execution unit. The print execution unit repeatedly performs ejection processing of ejection droplet of color material onto a printing medium. The controller is configured to perform: specifying an estimate value for a target pixel image by using at least one pixel value corresponding to at least one of a plurality of pixels included in target partial data representing the target partial image, the target partial image being selected among a plurality of partial images included in an N-th band image and representing a part of an object; specifying an object type of the object; and determining an ejection execution direction with respect to an N-th ejection processing to be one of a first direction and a second direction according to the estimate value and the object type.

An image processing apparatus includes a controller for controlling a print execution unit. The print execution unit repeatedly performs ejection processing of ejecting a droplet of color material onto a printing medium. The controller is configured to perform: specifying an estimate value for a target partial image by using color gap information, the target partial image being selected among a plurality of partial images included in an N-th band image; determining whether the estimate value satisfies an estimate condition; determining an ejection execution direction with respect to an N-th ejection processing to be a first direction in response to determination that the estimate value satisfies the estimate condition; and determining the ejection execution direction with respect to the N-th ejection processing to be opposite to the ejection execution direction with respect to an (N1)-th ejection processing in response to determination that the estimate value does not satisfy the estimate condition.

Selecting nozzles can include selecting nozzles of a plurality of nozzles to print a portion of a print job based on content of the print job and assigning firing reservations to the selected nozzles, where a total number of the firing reservations assigned to the selected nozzles is comparatively less than a total number of the plurality of nozzles.

A printing device includes a discharge control unit configured to, with a first movement of a printing head, among a one end side nozzle group using nozzles of one end side of a nozzle row, an other end side nozzle group using nozzles of an other end side of the nozzle row, and a center nozzle group using nozzles of the nozzle row that do not correspond to the one end side nozzle group and the other end side nozzle group, discharge ink on a designated area on a print medium from the nozzles included in the center nozzle group and the other end side nozzle group, and with a second movement which is the movement of the printing head the next time after the first movement, discharge the ink on the designated area from the nozzles included in the center nozzle group and the one end side nozzle group.

A printhead including one or more fluid vias in fluid communication with a fluid supply, each of the one or more fluid vias being associated with a first number of heating elements, the heating elements being divided into groups of a second number of heating elements so as to form a number of primitive groups, and an electrical interface having at least one shift register that receives primitive address data to allow for selective application of electrical signals to the heating elements so that fluid is ejected from the printhead in accordance with image data, the number of primitive groups being dependent on the print resolution of the printhead so that a number of bits required for the at least one shift register to address each heater is independent of the print resolution of the printhead.