Television – Special applications – Film – disc or card scanning
Reexamination Certificate
1999-03-25
2001-08-21
Le, Vu (Department: 2613)
Television
Special applications
Film, disc or card scanning
C348S094000, C348S095000
Reexamination Certificate
active
06278483
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to image scanning of photographic film and the like.
BACKGROUND OF THE INVENTION
Standards Organizations such as ISO and ANSI or system specifications specify image area positioning tolerances by denoting the maximum and minimum capture area on photographic film for a given format (i.e., size 135, size 126, size 120, size 110, APS, etc.). The minimum and maximum print area requirements for a photofinisher are also specified. These image area positioning tolerances allow the location of the exposed image to vary. This variability in image location leads to positioning difficulties when the film is scanned by a film scanner and subsequently re-scanned by the same or a different scanner. A key problem existing in current imaging systems is the difficulty in accurately repositioning of the image to the exact location of the previous scanning session.
Presently, photographic film is manually or automatically positioned in a film gate with the aid of perforation or edge detection schemes. Such perforation and edge detection schemes inherently have substantial position variability to their design when compared to digital image pixel resolution. This position variability can result in misaligned images if they are repositioned between multiple scans by the same or by different pieces of equipment. Many scanners mechanically move the film under a CCD array sensing head and convert the analog into a digital image. Due to mechanical registration tolerances, the film strip may be positioned under the sensing head differently each time. If the film is scanned in a different scanner, additional variabilities such as mechanical and resolution differences are introduced. For these reasons, a system to more accurately and repeatedly register the digital image for each scan is desired.
DISCLOSURE OF THE INVENTION
It is an object of the present invention to provide a system to more accurately and repeatedly registering a digital image for each scan of photographic film.
It is another object of the present invention to provide for the reduction in scan-to-scan variability within a given scanner.
It is another object of the present invention to provide for the reduction in scan-to-scan variability between different scanners.
It is another object of the present invention to provide for resolution independence so that a desired pixel can be found despite the resolution.
It is another object of the present invention to provide fiducial marks on the photographic film to enable repeatable scanning, printing, and image manipulation. These marks will provide an absolute reference point from which to make corrections to the digital image.
According to a feature of the present invention, a process for obtaining image coordinates of pixels of a digital image scanned from an original image on photographic film that has at least two fiducial marks on the photographic film associated with the original image, the process comprising the steps of scanning an area of the photographic film, including the original image and the fiducial marks, with an original scan resolution to form an original digital image. The dimensional position of the fiducial marks in the original digital image is detected, and the dimensional distance |fid
1
−fid
2
| between pairs of the fiducial marks is determined. The number of pixels in the original digital image between the pairs of fiducial marks is determined, and image coordinates of a location R of a selected pixel of the original digital image are referenced with respect to the fiducial marks. The referencing is effected by computing a dimension-to-pixel conversion factor &agr; by dividing the dimensional distance |fid
1
−fid
2
| between pairs of the fiducial marks by the number of pixels in the original digital image between the pairs of fiducial marks, and storing the dimension-to-pixel conversion factor &agr;, the reference location R of the selected pixel, the original scan resolution, the dimensional distance |fid
1
−fid
2
| between pairs of the fiducial marks, and the number of pixels in the original digital image between the pairs of fiducial marks on the film.
According to a feature of the present invention, the process may further involve the additional steps of re-scanning the area of the photographic film with a re-scan resolution to form a re-scan digital image; detecting the position of the fiducial marks in the re-scan digital image; reading the dimension-to-pixel conversion factor &agr;, the reference location R of the selected pixel, the original scan resolution, the distance |fid
1
−fid
2
| between pairs of the fiducial marks, and the number of pixels in the original digital image between the pairs of fiducial marks stored on the film; determining the number of pixels in the re-scan digital image between the pairs of fiducial marks; computing a scanner tolerance correction factor &ggr; by dividing the number of pixels in the original digital image between the pairs of fiducial marks by the number of pixels in the re-scan digital image between the pairs of fiducial marks; computing a resolution scaling factor &rgr; by dividing the re-scan resolution by the original scan resolution; and determining corrected image coordinates of the location R
corrected
of the selected pixel by multiplying the reference location R of the selected pixel, the scanner tolerance correction factor &ggr;, the resolution scaling factor &rgr;, and the dimension-to-pixel conversion factor &agr;.
The invention, and its objects and advantages, will become more apparent in the detailed description of the preferred embodiments presented below.
REFERENCES:
patent: 3234863 (1966-02-01), Peterson et al.
patent: 3409796 (1968-11-01), Money
patent: 4777515 (1988-10-01), Aikoh et al.
patent: 4837711 (1989-06-01), Suzuki
patent: 5198857 (1993-03-01), Goto
patent: 5198907 (1993-03-01), Walker et al.
patent: 5585886 (1996-12-01), Yabe
patent: 5587752 (1996-12-01), Petruchik
patent: 5606379 (1997-02-01), Williams
Eastman Kodak Company
Le Vu
Sales Milton S.
LandOfFree
Image registration on repeated scans using fiducial marks does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image registration on repeated scans using fiducial marks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image registration on repeated scans using fiducial marks will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2533333