US5751838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Correction of camera motion between two image frames
Assignee: NEC Corp
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Filing: 1996-01-26
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Granted: 1998-05-12
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Expires: 2016-01-26
Abstract
Abstract A technique for determining the ego-motion between two frames of an image that includes estimating likely values of the translation and rotation and making a five-dimensional search over the space of likely translations and rotations and finding the global minimum at the current motion estimate by a sum of squared differences cost function.
Inventors
- 👤 Ingemar J. Cox
- 👤 Sebastien Roy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:40
CPC Classifications
G; G06; G06T; G06T7/00; G06T7/20; G06T7/246; G06V; G06V10/00; G06V10/10; G06V10/12; G06V10/14; G06V10/147
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
89 words
A process for determining ego-motion between two image frames of a scene that includes the steps of: estimating the two parameters of translation and three parameters of rotation involved in camera ego-motion based upon pixels in one frame and corresponding epipolar line segments in the other frames; computing the cost function of the estimated movement; and revising the estimate and computing the cost function in iterative fashion to find the estimate that results in the cost function with the least figure of merit for use as the desired ego-motion.
Claim 2
Dependent Claim
89 words
A process for determining ego-motion between two image frames of a scene that includes the steps of: estimating the two parameters of translation and three parameters of rotation involved in camera ego-motion based upon pixels in one frame and corresponding epipolar line segments in the other frames; computing the cost function of the estimated movement; and revising the estimate and computing the cost function in iterative fashion to find the estimate that results in the cost function with the least figure of merit for use as the desired ego-motion.
Claim 3
Dependent Claim
36 words
The process of claim 1 in which the cost function depends on the sum of squared differences between pixels of one image and sample points along the assumed corresponding epipolar line segments in the other image.
Claim 4
Dependent Claim
22 words
The process of claim 1 that includes as a preliminary stop the normalization of the pixel intensity levels of the two frames.
Claim 5
Dependent Claim
15 words
The process of claim 3 in which the normalization is done by dynamic histogram warping.
Claim 6
Independent Claim
120 words
A method for deriving a measure of the camera translation involved between two image frames of a given scene that have an assumed known rotation and an unknown translation comprising the steps of: selecting a point A in the first frame; computing the corresponding zero disparity point in the second frame; selecting a plurality of different line segments that pass through the zero disparity point and are oriented as possible candidates for the focus of expansion; selecting a number of points on each of the line segments; calculating the error measures of each of the selected lines for finding the one with the minimum error; and using the one with the minimum error for identifying the true focus of expansion.
Claim 7
Independent Claim
120 words
A method for deriving a measure of the camera translation involved between two image frames of a given scene that have an assumed known rotation and an unknown translation comprising the steps of: selecting a point A in the first frame; computing the corresponding zero disparity point in the second frame; selecting a plurality of different line segments that pass through the zero disparity point and are oriented as possible candidates for the focus of expansion; selecting a number of points on each of the line segments; calculating the error measures of each of the selected lines for finding the one with the minimum error; and using the one with the minimum error for identifying the true focus of expansion.
Claim 8
Independent Claim
120 words
A method for deriving a measure of the camera rotation involved between two image frames of a given scene that have an assumed known translation and an unknown rotation comprising the steps of: selecting a point A in the first frame; computing the corresponding zero disparity point in the second frame; selecting a plurality of different line segments that pass through the possible candidate zero disparity points and are oriented according to the focus of expansion; selecting a member of points on each of the line segments; calculating the error measures of each of the selected lines for finding the one with the minimum error; and using the one with the minimum error for identifying the true focus of expansion.
Claim 9
Independent Claim
120 words
A method for deriving a measure of the camera rotation involved between two image frames of a given scene that have an assumed known translation and an unknown rotation comprising the steps of: selecting a point A in the first frame; computing the corresponding zero disparity point in the second frame; selecting a plurality of different line segments that pass through the possible candidate zero disparity points and are oriented according to the focus of expansion; selecting a member of points on each of the line segments; calculating the error measures of each of the selected lines for finding the one with the minimum error; and using the one with the minimum error for identifying the true focus of expansion.
Claim 10
Dependent Claim
22 words
The process of claim 5 that includes as a preliminary step the normalization of the pixel intensity levels of the two frames.
Claim 11
Dependent Claim
22 words
The process of claim 6 that includes as a preliminary step the normalization of the pixel intensity levels of the two frames.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-11 | 2001-11-10 | 2002-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-11 | 2005-11-10 | 2006-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-11 | 2009-11-10 | 2010-05-12 | $7700.00 | Window Closed / Lapsed |