Patent ID: 8104857

Claim:
A method of calculating a correction value, the method comprising: forming a test pattern in which a dot row formed by aligning dots in a direction intersecting a predetermined direction is aligned in the predetermined direction on a medium and forming information on the test pattern on the medium, by using a first nozzle group of a liquid ejecting apparatus that includes a nozzle row, in which a plurality of nozzles ejecting liquid is aligned in the predetermined direction, having the first nozzle group and a second nozzle group; forming a test pattern in which a dot row formed by aligning dots in the intersecting direction is aligned in the predetermined direction on a medium and forming information on the test pattern on the medium, by using the second nozzle group of the liquid ejecting apparatus; acquiring two read-out data values by individually reading out the two media by using a scanner; and identifying the information included in the read-out data values, calculating a correction value of the first nozzle group based on the test pattern included in the read-out data values in a case where the information included in the read-out data values represents that the test pattern is formed by the first nozzle group, and calculating a correction value of the second nozzle group based on the test pattern included in the read-out data values in a case where the information included in the read-out data values represents that the test pattern is formed by the second nozzle group.