A method of processing image data, to obtain image data for printing a junction area connecting a circular pad having a radius R with a linear line pattern by forming ink blots having a radius r in an overlapping manner, includes: setting a base pitch P as a base distance between adjacent ink blots; arranging image data of the pad, line pattern, and junction area, which is defined by an extension of the line pattern, in an x-y coordinate system; selecting a first determination point, which corresponds to one side of the junction area; comparing a distance from a center of the pad to the first determination point with a value of (R−r+P); and storing coordinates of the first determination point as print data if the distance from the center of the pad to the first determination point is greater than or equal to the value of (R−r+P).