Abstract

A method of specifying each of the frame numbers of image frames of an elongated photographic film when the film is fed to be positioned in a printing position at which the film is to be subjected to printing. Position specifying areas are set at even intervals in the longitudinal direction of the film in such a manner as to include in the areas frame numbers. The frame number within one of the position specifying areas is specified as the frame number of one of the image frames if the center of the one image frame is present in the one position specifying area. Non-specifying areas which are in the vicinity of the boundaries of the position specifying areas but which do not belong to any of the frame numbers are also set. If the center of one of the image frames is present in one of the non-specifying areas, the number of this image is specified by referring to the frame numbers of the image frames ahead of and behind that one image frame. The method is therefore capable of specifying each of the frame numbers in such a manner that they form a sequence of numbers or a series of symbols that possesses a certain regularity throughout the length of one photographic film.