(12) United States Patent ao) Patent No.: us 7,006,086 B2
Albeck et al. (45) Date of Patent: Feb. 28,2006
(54) METHOD AND APPARATUS FOR
ACCURATE ALIGNMENT OF IMAGES IN
DIGITAL IMAGING SYSTEMS BY
MATCHING POINTS IN THE IMAGES
CORRESPONDING TO SCENE ELEMENTS
(75) Inventors: Dan Albeck, Giv'at Shmuel (IL); Ron Gershon, Rehovot (IL); Avner Segev, Raanana (IL)
(73) Assignee: Cognitens Ltd., Ramat Hasharon (IL)
( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 314 days.
(21) Appl. No.: 10/025,175
(22) Filed: Dec. 19, 2001
(65) Prior Publication Data
US 2002/0140670 Al Oct. 3, 2002
(51) Int. CI.
G09G 5/00 (2006.01)
(52) U.S. CI 345/419; 345/156
(58) Field of Classification Search 345/419,
345/619, 420,156; 382/154, 276, 287, 291; 356/601-603; 348/370; 358/474,488 See application file for complete search history.
(56) References Cited
U.S. PATENT DOCUMENTS
5,644,386 A * 7/1997 Jenkins et al 382/224
5,835,241 A * 11/1998 Saund 358/488
6,016,147 A * 1/2000 Gantt 345/419
6,125,197 A * 9/2000 Mack et al 382/154
6,466,701 Bl * 10/2002 Ejiri et al 382/287
6,771,394 Bl * 8/2004 Nakanishi et al 358/474
2002/0033818 Al 3/2002 Lin 345/419
* cited by examiner
A digital imaging system is described that facilitates the location of anchors or targets in images of a scene. In one aspect, the digital imaging system makes use of differences as between the properties of the surfaces of the targets and the properties of the surfaces of the objects that are to be mensurated, reconstructed, etc., to facilitate providing uniform illumination of the targets when recording a set of images of the scene, thereby reducing noise that may arise in connection with determining the locations of the targets if they were illuminated by structured illumination, while contemporaneously providing that the objects can be illuminated by structured illumination when the images are recorded. In this aspect, the digital imaging system can use the positions of the targets in the images to relate a local coordinate system associated with the image set to a global coordinate system. In a second aspect, the digital imaging system makes use of one or more of a plurality of algorithms to determine the locations of targets in the images of the scene in the respective objects. In this aspect, the digital imaging system records two sets of images, including a baseline set and a working set. The baseline set is recorded using uniform illumination, with the baseline set comprising only images of the targets. The working set is recorded using structured illumination, with the working set comprising image of both the targets and the objects. The working set is used in connection with mensuration, virtual reconstruction, etc., and one or more of the algorithms are used to determine the likely positions of the targets in the images in the working image set, and to determine transformations between the baseline and working image set such that the local coordinate system associated with the working image set can be related to the global coordinate system.
49 Claims, 7 Drawing Sheets