Image processing apparatus, image processing method, and storage medium for improving the quality of printed edges

An image processing method comprising:

• acquiring N-valued image data corresponding to an image including at least one object, and edge data indicating an edge area of the at least one object, wherein all of the edge area resides within the at least one object and constitutes a portion of the at least one object;
• generating M-valued (N>M≥2) quantized data that includes a plurality of pixels that correspond to the at least one object, which include pixels that correspond to the edge area of the at least one object, where each of the plurality of pixels is associated with one of a value indicating that no dot is to be recorded and a value indicating that a dot is to be recorded, by quantizing the N-valued image data, wherein the pixels that correspond to the edge area of the at least one object include pixels that have the value indicating that a dot is to be recorded interspersed with pixels that have the value indicating that no dot is to be recorded;
• and
• changing at least one pixel among the pixels that correspond to the edge area of the at least one object, as indicated by the edge data, and that have the value indicating that no dot is to be recorded in the quantized data so that the at least one pixel has the value indicating that the dot is to be recorded.

A non-transitory computer-readable storage medium storing a program for causing a computer to perform an image processing method comprising:

• acquiring N-valued image data corresponding to an image including at least one object, and edge data indicating an edge area of the at least one object, wherein all of the edge area resides within the at least one object and constitutes a portion of the at least one object;
• generating M-valued (N>M≥2) quantized data that includes a plurality of pixels that correspond to the at least one object, which include pixels that correspond to the edge area of the at least one object, where each of the plurality of pixels is associated with one of a value indicating that no dot is to be recorded and a value indicating that a dot is to be recorded, by quantizing the N-valued image data, wherein the pixels that correspond to the edge area of the at least one object include pixels that have the value indicating that a dot is to be recorded interspersed with pixels that have the value indicating that no dot is to be recorded;
• and
• changing at least one pixel among the pixels that correspond to the edge area of the at least one object, as indicated by the edge data, and that have the value indicating that no dot is to be recorded in the quantized data so that the at least one pixel has the value indicating that the dot is to be recorded.