Image processing method, image processing apparatus and storage medium

An image processing apparatus comprising:

• a unit configured to obtain gradation data for expressing a predetermined gradation value on a print medium by printing a first dot pattern and a second dot pattern on the print medium in an overlapping manner;
• and
• a unit configured to generate data for printing the first dot pattern and data that causes the print head to print the second dot pattern based on the gradation data corresponding to the predetermined gradation value, wherein
• the first dot pattern and the second dot pattern are each a lattice pattern in which a position of any dot to a position of a dot other than the any dot is specified by two basis vectors and are lattice patterns that vary in a combination of the two basis vectors,
• a combined dot pattern formed by superimposing any dot included in the first dot pattern and any dot included in the second dot pattern one on top of the other includes a superimposed dot that is formed by superimposing of one dot included in the first dot pattern and one dot included in the second dot pattern and a neighboring dot in which one dot included in the first dot pattern and one dot included in the second dot pattern are arranged at an interval smaller than a lattice spacing defined by the basis vectors, and
• the neighboring dot includes a plurality of neighboring dots varying in tilt of a straight line connecting a center of the one dot in the first dot pattern and a center of the one dot in the second dot pattern forming the neighboring dot.

A non-transitory computer-readable storage medium storing a program for causing one or more processors of a computer to execute an information processing method, the image processing method comprising the steps of:

• obtaining gradation data for expressing a predetermined gradation value on a print medium by printing a first dot pattern and a second dot pattern on the print medium in an overlapping manner;
• and
• generating data for printing the first dot pattern and data that causes the print head to print the second dot pattern based on the gradation data corresponding to the predetermined gradation value, wherein
• the first dot pattern and the second dot pattern are each a lattice pattern in which a position of any dot to a position of a dot other than the any dot is specified by two basis vectors and are lattice patterns that vary in a combination of the two basis vectors,
• a combined dot pattern formed by superimposing any dot included in the first dot pattern and any dot included in the second dot pattern one on top of the other includes a superimposed dot that is formed by superimposing of one dot included in the first dot pattern and one dot included in the second dot pattern and a neighboring dot in which one dot included in the first dot pattern and one dot included in the second dot pattern are arranged at an interval smaller than a lattice spacing defined by the basis vectors, and
• the neighboring dot includes a plurality of neighboring dots varying in tilt of a straight line connecting a center of the one dot in the first dot pattern and a center of the one dot in the second dot pattern forming the neighboring dot.