1. A method of discriminating between full size and panoramic images interspersed on a strip of film, a panoramic frame area being nested within a full size frame area leaving a non-panoramic frame area which is within the full size frame area but outside the panoramic frame area, the method comprising the steps of: (a) determining from a film density datum value of at least one pixel in the non-panoramic frame area if the image is a full size image and, if not, (b) then performing a longitudinal edge detection operation to determine from film density data values of pixels in both the panoramic and non-panoramic frame areas if an edge exists between the two areas and, if so, the existence of a panoramic image is determined and, if not, a full size image is determined.