Self calibrating scanner with single or multiple detector arrays and single or multiple optical systems

A method of scanning an object and storing pixel signals representative of an image of the object using a scanning device, comprising:

• positioning a job sheet adjacent the object, with the job sheet containing markings in shapes from which distinct points on the job sheet can be identified and located;
• scanning the object and the job sheet in successive partially overlapping swaths to produce electrical signals representing pixels of the image of the object and of the markings of the job sheet;
• identifying distinct points in the job sheet from the markings in overlapping portions of the swaths and matching the distinct points identified from one of the partially overlapping swaths to the same distinct points from another one of the overlapping swaths;
• deriving error values representing position errors of the scanning device from apparent spatial differences in location of the matching distinct points in the swaths;
• adjusting said electrical signals representing pixels of the planar object with said error values;
• and
• storing pixel signals representing said adjusted electrical signals representing pixels of the planar object in a memory.

A method of scanning and storing pixel signals representative of an object image using a scanning device, comprising:

• scanning the object image and a job sheet positioned adjacent said object image, wherein said object image and said job sheet are located in a first scanning plane, to produce electrical signals representing said object image and said job sheet;
• supplying position signals representing coordinates of the scanning device relative to said first scanning plane;
• determining repeatable position and attitude error of the scanning device;
• adjusting said electrical signals representing the object image and said job sheet with said position signals by forward sampling to remove effects created by said repeatable position and attitude error;
• and
• storing pixel signals representing said adjusted electrical signals representing the object image in a memory.

Image scanning apparatus for scanning and digitizing an object image, comprising:

• a job sheet positioned adjacent the object image;
• a first photoreceptor positioned adjacent, but spatially separated from the object image and the job sheet;
• a reseau;
• a second photoreceptor positioned adjacent, but spatially separated from, said reseau;
• and
• a carrier capable of holding said first photoreceptor and said second photoreceptor in fixed spatial relationship to each other and for moving said first photoreceptor and said second photoreceptor relative to the reseau and relative to the object image, wherein said first photoreceptor is oriented such that, during scanning of said object image and said job sheet by said first photoreceptor, light detected by said first photoreceptor does not pass through or reflect off of said reseau prior to being detected by said first photodetector, and further wherein said second photoreceptor is oriented such that, during said scanning of said reseau by said second photoreceptor, light detected by said second photoreceptor does not pass through or reflect off the object image prior or the job sheet prior to being detected by said second photoreceptor.

A photogrammetric apparatus comprising:

• a planar object to be scanned for digital storage;
• a job sheet to be scanned simultaneously with the planar object;
• a reseau to be scanned simultaneously with the planar object;
• a light source positioned such that said planar object, said job sheet, and said reaseau are illuminated;
• a reseau photoreceptor capable of converting an image of the reseau focused thereon to reseau electrical signals;
• a planar object photoreceptor distinct from said reseau photoreceptor and capable of converting an image of the planar object and the job sheet focused thereon to object electrical signals;
• and
• optics capable of focusing light produced by said light source means when said light source illuminates the reseau, the job sheet, and the planar object such that images are formed of the reseau onto the reseau photoreceptor and images of the planar object and the job sheet are formed onto the planar object photoreceptor means.