Image processing apparatus controlling printing according to unidirectional printing method or bidirectional printing method

A non-transitory computer readable storage medium storing a set of program instructions for an image processing apparatus, the image processing apparatus controlling a print execution unit including:

• a print head moving in a main scanning direction including a first direction and a second direction opposite the first direction, the print head including a first nozzle configured to eject first type ink, and a second nozzle configured to eject second type ink, the second nozzle being positioned apart from the first nozzle in the main scanning direction;
• a main scanning unit configured to perform a main scan, the main scan including a first main scan to move the print head in the first direction as a printing direction, and a second main scan to move the print head in the second direction as the printing direction;
• and a sub scanning unit configured to perform a sub scan to move a recording sheet relative to the print head in a sub scanning direction crossing the main scanning direction, the print execution unit performing printing a target image on the recording sheet by alternately executing a partial print and the sub scan a plurality of times, the target image being based on target image data having a plurality of sets of partial image data representing respective ones of a plurality of partial images in the target image, the partial print being one of a first partial print and a second partial print, wherein in the first partial print the print head forms dots on the recording sheet for printing a partial image in the target image while the main scanning unit performs the first main scan, the first partial print being capable of printing colors forming a first color gamut, wherein in the second partial print the print head forms dots on the recording sheet for printing a partial image in the target image while the main scanning unit performs the second main scan, the second partial print being capable of printing colors forming a second color gamut, the first color gamut including a common gamut and a first special gamut, the second color gamut including the common gamut and a second special gamut different from the first special gamut, the image processing apparatus including a memory storing a first color conversion profile, a second color conversion profile, and a third color conversion profile, each of the first color conversion profile, the second color conversion profile, and the third color conversion profile being used for converting a first type color value into a second type color value having a plurality of component values corresponding to respective ones of a plurality of types of ink including the first type ink and the second type ink, the first color conversion profile and the second color conversion profile being adjusted so that a first printed color approaches a second printed color, wherein the first printed color is printed through the first partial print based on a first converted color value which is one of the second type color value converted from an original color of the first type color value by using the first color conversion profile, and the second printed color is printed through the second partial print based on a second converted color value which is one of the second type color value converted from the original color by using the second color conversion profile, the first color conversion profile being used for generating data for performing the first partial print in a bidirectional printing method, the second color conversion profile being used for generating data for performing the second partial print in the bidirectional printing method, the third color conversion profile being used for generating data for a unidirectional printing method, wherein in the bidirectional printing method the print execution unit prints the target image using both the first partial print and the second partial print, and in the unidirectional printing method the print execution unit prints the target image using the first partial print without using the second partial print, wherein when the first partial print prints colors based on color values of the second type color value converted from original color values of the first type color value by using the first color conversion profile, a color gamut formed by the colors printed by the first partial print includes the common gamut and excludes at least part of the first special gamut, wherein when the second partial print prints colors based on color values of the second type color value converted from original color values of the first type color value by using the second color conversion profile, a color gamut formed by the colors printed by the second partial print includes the common gamut and excludes at least part of the second special gamut, wherein when the first partial print prints colors based on color values of the second type color value converted from original color values of the first type color value by using the third color conversion profile, a color gamut formed by the colors printed by the first partial print includes the common gamut and the first special gamut, the set of program instructions comprising:
• setting a target printing method for printing the target image on the recording sheet to one of a plurality of printing methods including the bidirectional printing method and the unidirectional printing method;
• in a case where the bidirectional printing method is set as the target printing method:
• executing both a first generation process and a second generation process, the first generation process generating first partial print data by converting a set of partial image data using the first color conversion profile, the second generation process generating second partial print data by converting another set of partial image data using the second color conversion profile;
• and
• controlling the print execution unit to perform printing according to the bidirectional printing method by using the first partial print data for the first partial print and the second partial print data for the second partial print;
• and
• in a case where the unidirectional printing method is set as the target printing method:
• executing a third generation process generating third partial print data by converting a set of partial image data using the third color conversion profile;
• and
• controlling the print execution unit to perform printing according to the unidirectional printing method by using the third partial print data for the first partial print.