US5612743A
Expired / Lapsed
US
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Method for encoding a video signal using feature point based motion estimation
Assignee: WiniaDaewoo Co Ltd
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Filing: 1995-07-05
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Granted: 1997-03-18
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Expires: 2015-07-05
Abstract
Abstract A method for adaptively selecting feature points according to motions of objects between the current frame and the reference frame, comprising: detecting a motion vector for each pixel in the current frame between the current frame and the reference frame; providing a pixel value from the reference frame based on the motion vector for each pixel in the current frame; subtracting the pixel value provided from the reference frame from a pixel value of said each pixel of the current frame to thereby provide a differential pixel value; comparing the differential pixel value with a threshold value TH and selecting regions having their respective differential pixel values larger than the threshold value TH; shifting the pixels within the selected regions to positions indicated by their respective motion vectors to thereby provide shifted regions; detecting edge points from the reference frame; determining processing regions from the shifted regions, wherein the shifted regions are overlapped with a portion of the edge points; generating a first grid on the reference frame and a second grid for each of the processing regions, wherein the second grid is formed by a portion of grid points of the first grid and newly added grid points; and selecting, as the feature points, a multiplicity of pixels in the reference frame based on the first and the second grids and the edge points.
Inventors
- 👤 Min-Sup Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:03
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/50; H04N19/503; H04N19/51; H04N19/537; H04N19/54
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
326 words
A method, for use in a video signal encoder for encoding a digital video signal based on a feature point-based motion estimation technique, said digital video signal having a plurality of frames including a current frame and a reference frame, for adaptively selecting feature points according to motions of objects between the current frame and the reference frame, comprising: (a) detecting a motion vector for each pixel in the current frame between the current frame and the reference frame; (b) providing a pixel value from the reference frame based on the motion vector for each pixel in the current frame; (c) subtracting the pixel value provided from the reference frame from a pixel value of said each pixel of the current frame to thereby provide a differential pixel value; (d) comparing on a pixel-by-pixel basis the differential pixel value with a threshold value TH and selecting one or more regions, each of the selected regions consisting of the pixels having their respective differential pixel values larger than the threshold value TH; (e) shifting the pixels within the selected regions to positions indicated by their respective motion vectors to thereby provide shifted regions; (f) detecting edge points from the reference frame; (g) determining none or more processing regions from the shifted regions, wherein the processing regions are the shifted regions which overlap with a portion of the edge points; (h) generating a first grid on the reference frame and generating a second grid for each of the processing regions, wherein the second grid is formed by a portion of grid points of the first grid and newly added grid points, each of the newly added grid points being positioned at the center of a pair of neighboring grid points of the first grid in a horizontal or a vertical direction; and (i) selecting, as the feature points, a multiplicity of pixels in the reference frame based on the first and the second grids and the edge points.
Claim 2
Independent Claim
326 words
A method, for use in a video signal encoder for encoding a digital video signal based on a feature point-based motion estimation technique, said digital video signal having a plurality of frames including a current frame and a reference frame, for adaptively selecting feature points according to motions of objects between the current frame and the reference frame, comprising: (a) detecting a motion vector for each pixel in the current frame between the current frame and the reference frame; (b) providing a pixel value from the reference frame based on the motion vector for each pixel in the current frame; (c) subtracting the pixel value provided from the reference frame from a pixel value of said each pixel of the current frame to thereby provide a differential pixel value; (d) comparing on a pixel-by-pixel basis the differential pixel value with a threshold value TH and selecting one or more regions, each of the selected regions consisting of the pixels having their respective differential pixel values larger than the threshold value TH; (e) shifting the pixels within the selected regions to positions indicated by their respective motion vectors to thereby provide shifted regions; (f) detecting edge points from the reference frame; (g) determining none or more processing regions from the shifted regions, wherein the processing regions are the shifted regions which overlap with a portion of the edge points; (h) generating a first grid on the reference frame and generating a second grid for each of the processing regions, wherein the second grid is formed by a portion of grid points of the first grid and newly added grid points, each of the newly added grid points being positioned at the center of a pair of neighboring grid points of the first grid in a horizontal or a vertical direction; and (i) selecting, as the feature points, a multiplicity of pixels in the reference frame based on the first and the second grids and the edge points.
Claim 3
Dependent Claim
143 words
The method in accordance with claim 1, wherein said step(f) for detecting the edge points includes the step of generating a gradient magnitude for each pixel in the reference frame; and said step(i) of selecting the feature points includes the steps of: (i1) assigning a non-overlapping search range for each of the grid points of the first and the second grids; (i2) providing an edge value for each of the edge points, wherein the edge value is obtained by summing up the gradient magnitudes of the pixels within a block of pixels including said each of the edge points; and (i3)determining, as a feature point, each grid point which includes none of the edge points within its search range and each edge point having a largest edge value among one or more edge points within a search range, thereby providing the feature points.
Claim 4
Dependent Claim
25 words
The method in accordance with claim 2, wherein said step(a) of detecting the motion vector is carried out through the use of a block-matching technique.
Claim 5
Dependent Claim
20 words
The method in accordance with claim 2, wherein the first and the second grids are hexagonal and triangular grids, respectively.
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) | 2000-03-17 | 2000-09-16 | 2001-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-17 | 2004-09-16 | 2005-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-17 | 2008-09-16 | 2009-03-18 | $7700.00 | Window Closed / Lapsed |