METHOD FOR DETECTING/PROCESSING IMAGE INFORMATION

In a photographic printing system, it is necessary to measure the density of an original film to determine its exposure value and to precisely control conveyance/suspension of the original film in order to optimally print the images of each frame. When an image sensor is used for measurement, the image sensor should have a relatively rough picture element density in order to perform the calculation of the exposure value at high speed, but should also have a fine density in order to precisely control the conveyance of the original film. In order to resolve the dilemma, image information from the original film is detected with an image sensor of a relatively low resolution, and then the resolution is increased by picture element pitch interpolation through moving the original film at a minute pitch, thereby achieving precise and fast detection and processing of image information.