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US 5,471,544 AGranted
Condition number-based smoothins of optical flow fields
OwnerVishal Markandey, Bruce E. Flinchbaughinventors
Life of this patent
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Abstract
An image processor (10) is provided in which imaging data obtained by an image sensor (12) is processed for purposes of detecting motion. An optical flow field generator (16) processes the image data to provide condition number-based smoothed optical flow vectors, and stores those smoothed vectors in memory (18). The optical flow field stored in memory (18) is accessed and further processed by analyzer (20) for purposes of providing users with information on the motion of objects in the image plane of image sensor (12). Such user information may be displayed on a monitor (22).
Claims20
A method of processing images, comprising the steps of:
- generating an image signal in an image sensor;
- transmitting the image signal to an optical flow field generator device;
- generating a plurality of optical flow vectors in an initial flow field in said generator device;
- generating in said generator device a condition number for each of the optical flow vectors dependent on an image intensity of said image signal at each associated pixel location;
- smoothing in said generator device the initial optical flow field by minimizing each sum of a lack of accuracy and a product of the condition number and a lack of smoothness for each optical flow vector;
- storing the smoothed optical flow field in a memory;
- and
- processing the smoothed optical flow field.
5 more elements
A method of processing images, comprising the steps of:
- generating an image signal in an image sensor;
- transmitting the image signal to an optical flow field generator device;
- generating a plurality of optical flow vectors in an initial flow field in said generator device;
- generating at said generator device a condition number for each of the optical flow vectors dependent on an image intensity of said image signal at each associated pixel location;
- smoothing the initial optical flow field by minimizing each sum of the lack of accuracy and the product of the condition number and the lack of smoothness for each optical flow vector in said generator device;
- and
- processing said optical flow filed to indicate or track motion.
4 more elements
An image processor, comprising:
- an image sensor device for generating an image signal;
- circuitry for transmitting said image signal to an optical flow field generator;
- said optical flow field generator being operable to generate a condition number-based smoothed optical flow field from said image signal;
- said condition number-based flow field being dependent on a condition number dependent on the image intensity of said image signal at each signal location of an associated optical flow vector;
- a memory coupled to said optical flow field generator for storing said smoothed optical flow field;
- and
- an analyzer for processing said smoothed optical flow field.
4 more elements
A method of processing images, comprising the steps of:
- generating an image signal in an image sensor;
- transmitting the image signal to an optical flow field generator device;
- generating a plurality of optical flow vectors in an initial flow field in said generator device;
- generating in said generator device a condition number c for each of optical flow vectors (u,v) where:
- c=.parallel.E.parallel.E.sup.-1 .parallel.
- where .parallel.E.parallel. is the square root as the largest eigenvalue of E.sup.T E, where matrix E is:
- ##EQU5## E.sub.T is the transpose of E or ##EQU6## and the terms A,B,D,E are derivatives of image intensity at the pixel location associated with the flow vector and are determined from:
- Au+Bv+C=0
- Du+Ev+F=0
- used to solve for (u,v);
- smoothing the initial optical flow field by minimizing each sum of a lack of accuracy and a product of the condition number and a lack of smoothness for each optical flow vector;
- and
- processing said optical flow field to indicate or track motion.
10 more elements
An image processor, comprising:
- an image sensor for generating an image signal;
- circuitry for transmitting said image signal to an optical flow field generator;
- said optical flow field generator including means for generating a plurality of optical flow vectors in an initial optical flow field from said image signal, means for generating a condition number for each of said optical flow vectors having a number value dependent on an image intensity of said image signal at each associated pixel location, and means responsive to said condition number and said initial optical flow field for generating a smoothed optical flow field by minimizing each sum of a lack of accuracy and a product of said condition number and a lack of smoothness for each optical flow vector;
- and
- circuitry for processing said smoothed optical flow field to indicate or track motion.
2 more elements
Dependencies are inferred from the claim text.