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US7046731B2
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Extracting key frames from a video sequence
Assignee: Canon Inc
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Filing: 2001-01-08
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Granted: 2006-05-16
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Expires: 2021-01-08
Abstract
Abstract A method of extracting key frames from a video sequence, which video sequence comprises MPEG compressed video data having block motion vectors. The method initially partially decompresses ( 202 ) the MPEG compressed video data to obtain block motion vectors and converts ( 204 ) the block motion vectors to forward block motion vectors. The method then generates ( 206 ) global motion signals and generates ( 306 ) dominant global direction clusters. The method then selects ( 402, 404, 406 ) potential key frames of the video sequence using the generated dominant global direction clusters. The method lastly decompresses ( 408 ) the selected key frames to obtain the extracted key frames.
Inventors
- 👤 Jing Wu
- 👤 Alison Joan Lennon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:02
CPC Classifications
G; G11; G11B; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G06; G06F; G06F16/00; G06F16/70; G06F16/71; G06F16/78; G06F16/783; G06F16/7847; G06F16/786; H; H04; H04N; H04N19/00; H04N19/10; H04N19/134; H04N19/142; H04N19/169; H04N19/179; H04N19/85; H04N19/87; H04N5/00; H04N5/14; H04N5/147
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
126 words
A method of extracting key frames from a video sequence, wherein the video sequence comprises compressed video data having motion vectors; the method comprising the steps of: generating, for each frame of a plurality of frames of the video sequence, global motion signals based on the motion vectors, wherein the global motion signals are representative of a global motion of the frame; determining for each frame of the plurality of frames of the video sequence, a dominant direction of the global motion of the frame from the generated global motion signals associated with the frame; clustering the plurality of frames according to their determined dominant directions; selecting key frames from the clusters of frames; and decompressing the selected key frames to obtain the extracted key frames.
Claim 2
Independent Claim
126 words
A method of extracting key frames from a video sequence, wherein the video sequence comprises compressed video data having motion vectors; the method comprising the steps of: generating, for each frame of a plurality of frames of the video sequence, global motion signals based on the motion vectors, wherein the global motion signals are representative of a global motion of the frame; determining for each frame of the plurality of frames of the video sequence, a dominant direction of the global motion of the frame from the generated global motion signals associated with the frame; clustering the plurality of frames according to their determined dominant directions; selecting key frames from the clusters of frames; and decompressing the selected key frames to obtain the extracted key frames.
Claim 3
Dependent Claim
25 words
A method as claimed in claim 1 , wherein said selecting step comprises selecting key frames from the clusters using a set of predefined rules.
Claim 4
Dependent Claim
58 words
A method as claimed in claim 1 , wherein said selecting step comprises the substeps of: selecting potential key frames of the video sequence from the clusters using a first set of predefined rules; and removing redundant key frames from the selected potential key frames using a second set of predefined rules resulting in the selected key frames.
Claim 5
Dependent Claim
87 words
A method as claimed in claim 1 , wherein said selecting step comprises the substeps of: selecting potential key frames of the video sequence from the clusters using a first set of predefined rules; removing redundant key frames from the selected potential key frames using a second set of predefined heuristic rules resulting in a set of selected potential key frames; and removing similar and/or repeated key frames from the set of selected potential key frames using a color histogram technique resulting in the selected key frames.
Claim 6
Dependent Claim
46 words
A method as claimed in claim 1 , wherein said step of generating global motion signals comprises generating, for each frame of the plurality of frames of the video sequence, a pan global motion signal, a zoom global motion signal, and a tilt global motion signal.
Claim 7
Dependent Claim
37 words
A method as claimed in claim 1 , wherein the dominant global direction is selected from the group consisting of a pan left, pan right, tilt up, tilt down, zoom in, zoom out and global still direction.
Claim 8
Dependent Claim
71 words
A method as claimed in claim 1 , wherein said determining step comprises, for each frame, the sub-steps of: generating discrete global motion signals from the generated global motion signals; removing noise from the generated discrete global motion signals to produce noise reduced discrete global motion signals; and determining the dominant direction of the global motion of the frame from the noise reduced discrete global motion signals associated with the frame.
Claim 9
Dependent Claim
59 words
A method according to claim 1 , wherein the motion vectors are block motion vectors, and said step of generating global motion signals comprises the steps of: decompressing the compressed video data to obtain the block motion vectors; converting the block motion vectors to forward block motion vectors; generating global motion signals based on the forward block motion vectors.
Claim 10
Dependent Claim
17 words
A method according to claim 8 , wherein the compressed video data is MPEG compressed video data.
Claim 11
Dependent Claim
132 words
Apparatus for extracting key frames from a video sequence, wherein the video sequence comprises compressed video data having motion vectors; the apparatus comprising: means for generating, for each frame of a plurality of frames of the video sequence, global motion signals based on the motion vectors, wherein the global motion signals are representative of a global motion of the frame; means for determining, for each frame of the plurality of frames of the video sequence, a dominant direction of the global motion of the frame from the generated global motion signals associated with the frame; means for clustering the plurality of frames according to their determined dominant directions; means for selecting key frames from the clusters of frames; and means for decompressing the selected key frames to obtain the extracted key frames.
Claim 12
Dependent Claim
132 words
Apparatus for extracting key frames from a video sequence, wherein the video sequence comprises compressed video data having motion vectors; the apparatus comprising: means for generating, for each frame of a plurality of frames of the video sequence, global motion signals based on the motion vectors, wherein the global motion signals are representative of a global motion of the frame; means for determining, for each frame of the plurality of frames of the video sequence, a dominant direction of the global motion of the frame from the generated global motion signals associated with the frame; means for clustering the plurality of frames according to their determined dominant directions; means for selecting key frames from the clusters of frames; and means for decompressing the selected key frames to obtain the extracted key frames.
Claim 13
Dependent Claim
136 words
A computer readable medium comprising a computer program for extracting key frames from a video sequence, wherein the video sequence comprises compressed video data having motion vectors; the computer program comprising: code for generating, for each frame of a plurality of frames of the video sequence, global motion signals based on the motion vectors, wherein the global motion signals are representative of a global motion of the frame; code for determining, for each frame of the plurality of frames of the video sequence, a dominant direction of the global motion of the frame from the generated global motion signals; code for clustering the plurality of frames according to their determined dominant directions; code for selecting key frames from the clusters of frames; and code for decompressing the selected key frames to obtain the extracted key frames.
Claim 14
Dependent Claim
136 words
A computer readable medium comprising a computer program for extracting key frames from a video sequence, wherein the video sequence comprises compressed video data having motion vectors; the computer program comprising: code for generating, for each frame of a plurality of frames of the video sequence, global motion signals based on the motion vectors, wherein the global motion signals are representative of a global motion of the frame; code for determining, for each frame of the plurality of frames of the video sequence, a dominant direction of the global motion of the frame from the generated global motion signals; code for clustering the plurality of frames according to their determined dominant directions; code for selecting key frames from the clusters of frames; and code for decompressing the selected key frames to obtain the extracted key frames.
Claim 15
Independent Claim
136 words
An apparatus for extracting key frames from a video sequence, said apparatus comprising: a storage unit for storing the video sequence comprising compressed video data having motion signals; a processor coupled to the storage unit and adapted to: generate, for each frame of a plurality of frames of the video sequence, global motion signals based on the motion vectors, wherein the global motion signals are representative of a global motion of the frame; determine, for each frame of the plurality of frames of the video sequence, a dominant direction of the global motion of the frame from the generated global motion signals associated with the frame; cluster the plurality of frames according to their determined dominant directions; select key frames from the clusters of frames; and decompress the selected frames to obtain the extracted key frames.
Claim 16
Independent Claim
136 words
An apparatus for extracting key frames from a video sequence, said apparatus comprising: a storage unit for storing the video sequence comprising compressed video data having motion signals; a processor coupled to the storage unit and adapted to: generate, for each frame of a plurality of frames of the video sequence, global motion signals based on the motion vectors, wherein the global motion signals are representative of a global motion of the frame; determine, for each frame of the plurality of frames of the video sequence, a dominant direction of the global motion of the frame from the generated global motion signals associated with the frame; cluster the plurality of frames according to their determined dominant directions; select key frames from the clusters of frames; and decompress the selected frames to obtain the extracted key frames.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2009-05-15 | 2009-11-14 | 2010-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2013-05-15 | 2013-11-14 | 2014-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2017-05-15 | 2017-11-14 | 2018-05-16 | $7700.00 | Window Closed / Lapsed |