Image analysis – Image transformation or preprocessing – Measuring image properties
Reexamination Certificate
2000-10-02
2003-02-11
Couso, Jose L. (Department: 2621)
Image analysis
Image transformation or preprocessing
Measuring image properties
C348S171000
Reexamination Certificate
active
06519371
ABSTRACT:
BACKGROUND
Accurate computation of a centroid from a pre-defined window in an image plane is desirable for a number of space-based and commercial applications. The applications may include object tracking in robotic systems, autonomous navigation, image compression, and document copyright protection. Other applications may include space guidance and navigation systems, and deep-space optical communication systems that require accurate and stable beam pointing for high speed data transfer.
Off-focal-plane digital processors may yield accurate centroid values, but only at the cost of increased latency, power and size. On or near focal-plane centroid computation using current mode circuits, and neuro-MOS circuits have been implemented. However, neither approach may be compatibly integrated with high performance image sensors.
A photodiode-based active pixel imager (API) sensor may be used for high quality imaging applications such as the centroid computation. The photodiode-based sensor provides higher quantum efficiency than a photogate-based sensor. However, noise in the photodiode-type CMOS API sensors causes high reset (kTC) noise at the sense node.
SUMMARY
The present disclosure describes a centroid computation system having an imager array, a switching network, computation elements, and a divider circuit. The imager array has columns and rows of pixels. The switching network is adapted to receive pixel signals from the image array. The plurality of computation elements operates to compute inner products for at least x and y centroids. The plurality of computation elements has only passive elements to provide inner products of pixel signals the switching network. The divider circuit is adapted to receive the inner products and compute the x and y centroids.
REFERENCES:
patent: 5175802 (1992-12-01), Crookshanks
patent: 5463388 (1995-10-01), Boie et al.
patent: 5576763 (1996-11-01), Ackland et al.
patent: 5648642 (1997-07-01), Miller et al.
patent: 5693946 (1997-12-01), Vickers et al.
patent: 5825352 (1998-10-01), Bisset et al.
patent: 5835141 (1998-11-01), Ackland et al.
patent: 5854100 (1998-12-01), Chi
patent: 5867152 (1999-02-01), Sextro
patent: 6058223 (2000-05-01), Strohbehn
Yang, David X. et al., Advanced Focal Plane Arrays and Electronic Cameras, Journal: Proc. SPIE vol. 2950, p. 8-17, Thierry M. Bernard; Ed., Oct. 1996.
Fox, Eric C. et al., Solid State Sensor Arrays; Development and Applications II, Journal: Proc. SPIE vol. 3301, p. 17-26, Morley M. Blouke; Ed., Jan. 1998.
Cunningham Thomas J.
Hancock Bruce
Pain Bedabrata
Sun Chao
Yang Guang
California Institute of Technology
Couso Jose L.
Fish & Richardson P.C.
Patel Kanji
LandOfFree
High-speed on-chip windowed centroiding using... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High-speed on-chip windowed centroiding using..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-speed on-chip windowed centroiding using... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3160197