1. An image processing device comprising: a print control unit configured to cause a printing apparatus to print a setting sheet used for setting a value of at least one parameter for image processing, the setting sheet including sample images corresponding to values of the at least one parameter, the number of the sample images included on the setting sheet being smaller than the number of the values that can be designated by a user of the at least one parameter; an acquiring unit configured to acquire a sheet image obtained by reading, by a reading apparatus, of the setting sheet printed by the print control unit; a determining unit configured to determine a position of a mark given by a user on the setting sheet, based on the sheet image acquired by the acquiring unit; and a setting unit configured to set a value of the at least one parameter according to a position of the mark on the setting sheet determined by the determining unit, wherein, in a case where a position of the mark on the setting sheet determined by the determining unit corresponds to an area between two sample images included on the setting sheet, the setting unit sets a value between the values corresponding to the two sample images.