Film scanner which doubly scans to correct for film speed and position errors

A film scanner for optically scanning a film for obtaining a picture signal, which film is moving at a substantially constant speed, characterized in that the film scanner doubly scans parts of each film image and determines image position errors by comparing the two scanning signals of the same nominal image content, and corrects the picture signal in dependence upon the determined image position error, and in that two scanning sensors (11, 12) and one beam splitter arrangement are provided, which arrangement is adapted in such a way that the two scanning sensors (11, 12) scan different parts of the film which are spaced from each other by a defined distance.

A film scanner for optically scanning a film for obtaining a picture signal, which films is moving at a substantially constant speed, characterized in that the film scanner doubly scans parts of each film image and determines image position errors by comparing the two scanning signals of the same nominal image content, and corrects the picture signal in dependence upon the determined image position error, and in that a sensor arrangement (4) is provided which comprises a plurality of partially overlapping sensors (5, 6, 7, 8) and in that the overlapping sensor areas are used for double scanning.

A film scanner for optically scanning a film for obtaining a picture signal, which film is moving at a substantially constant speed, characterized in that the film scanner doubly scans parts of each film image and determines image position errors by comparing the two scanning signals of the same nominal image content, and corrects the picture signal in dependence upon the determined image position error, and in that a delay member (20) is provided which delays the first scanning signal by .tau.=Y.sub.0 /V.sub.0, with respect to time at a speed V.sub.0 of the film and a double scanning over a distance Y.sub.0 in the direction of travel of the film, in that an arrangement (21, 22) is provided which compares the first delayed scanning signal with the second scanning signal, a motion estimation being performed preferably by means of a block-matching method, yielding motion vectors dependent on which the image position errors in the picture signal are corrected by means of a correction element (24).