A processor of an information processing device acquires an image, determines base point from the image, and acquires first position information of the base point. The processor determines a reference direction indicating characteristics of color information of a section of the image around the base point. The processor acquires a sample for each of a plurality of reference points acquired sequentially in accordance with a predetermined condition from a starting point determined on the basis of the base point and the reference direction. The processor calculates as frequency information, frequency components of changes in the color information with respect to the second position information for the plurality of samples, using a linear prediction coefficient calculated using a Yule-Walker method without applying a window function. The processor causes the memory to store information associating the frequency information, the first position information and the reference direction, as collation information.