CORRECTION VALUE ACQUISITION METHOD, CORRECTION VALUE ACQUISITION PROGRAM, AND PRINTER

PROBLEM TO BE SOLVED: To acquire a correct density correction value for performing density correction for every dot train by automatically calculating a threshold value for removing foreign substances such as dust adhered to a test pattern.SOLUTION: (A) A pattern in which dot trains formed along an intersection direction that intersects a predetermined direction are arranged in the predetermined direction is formed on a medium by ejecting an ink from nozzle arrays arranged in the predetermined direction. (B) A predetermined threshold value is calculated by using a standard deviation of densities of the whole of pixels corresponding to the pattern in image data obtained by reading the pattern. (C) A density is calculated for every pixel train by using data of pixels whose density is in a range of the threshold value among the pixels that compose pixel trains corresponding to respective dot trains of the pattern. (D) A correction value corresponding to each dot train of the pattern is acquired on the basis of the density calculated for every pixel train.