Automatic object extraction
First Claim
1. A method for automatic extraction of objects in video sequences, each object represented by an array of pixels, the method comprising:
- a. providing at least a first and a second high frame rate video frames;
b. performing a reciprocal illumination correction of said first and second video frames to yield respective first and second smoothed frames;
c. performing a change detection operation between said first and second smoothed frames to obtain a difference image; and
d. performing a local adaptive thresholding operation on said difference image to generate a binary image containing extracted objects, said local thresholding operation using a weight test to determine a boundary of each of said extracted objects,whereby the extraction of said extracted objects by the method is automatic stable and robust, and whereby no advance knowledge of the video sequences is needed to achieve the extraction.
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Abstract
A method for automatic, stable and robust object extraction of moving objects in color video frames, achieved without any prior knowledge of the video content. For high rate video, the method includes providing at least a first and a second high frame rate video frames, performing a reciprocal illumination correction of the first and second video frames to yield respective first and second smoothed frames, performing a change detection operation between the first and second smoothed frames to obtain a difference image, and performing a local adaptive thresholding operation on the difference image to generate a binary image containing extracted objects, the local thresholding operation using a weight test to determine a boundary of each of the extracted objects. For an extracted object with a fragmented boundary, the method further comprises re-unifying the boundary. For low rate video, additional steps include: an edge correction applied on the first image to yield a first edge-corrected image, a global thresholding applied to the first edge-corrected image to yield a first binary edge image, and an ANDing operation on the difference image and the first binary edge image to generate a second binary image which is fed to the local adaptive thresholding operation.
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Citations
25 Claims
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1. A method for automatic extraction of objects in video sequences, each object represented by an array of pixels, the method comprising:
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a. providing at least a first and a second high frame rate video frames; b. performing a reciprocal illumination correction of said first and second video frames to yield respective first and second smoothed frames; c. performing a change detection operation between said first and second smoothed frames to obtain a difference image; and d. performing a local adaptive thresholding operation on said difference image to generate a binary image containing extracted objects, said local thresholding operation using a weight test to determine a boundary of each of said extracted objects, whereby the extraction of said extracted objects by the method is automatic stable and robust, and whereby no advance knowledge of the video sequences is needed to achieve the extraction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for automatic extraction of objects in video sequences, each object represented by an array of pixels, the method comprising:
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a. providing at least a first and a second low frame rate video frames; b. performing a reciprocal illumination correction of said first and second video frames to yield respective first and second smoothed frames; c. performing an edge detection operation on said first video frame to produce a first edge image; d. performing a change detection operation between said first and second smoothed frames to obtain a difference image; e. performing a global thresholding operation on said first edge image to produce a first binary edge image; f. ANDing said difference image and said first binary edge image to produce a first edge-corrected difference image; and g. performing a local adaptive thresholding operation on said first edge-corrected difference image to generate a second binary image containing extracted objects, said local thresholding operation using a weight test to determine a boundary of each of said extracted objects, whereby the extraction of said extracted objects by the method is automatic, stable and robust, and whereby no advance knowledge of the video sequences is needed to achieve the extraction. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method for automatic extraction of objects in color video sequences, each object represented by an array of pixels, the method comprising:
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a. providing at least a first and a second high frame rate video frames; b. obtaining a first edge image of said first video frame; c. obtaining a difference image based on first and second illumination corrected, smoothed frames derived from said first and second video frames respectively; d. performing a global thresholding operation on said first edge image to produce a first binary edge image; e. ANDing said difference image and said first binary edge image to produce a first edge-corrected difference image; and f. based on said first edge-corrected difference image, generating a second binary image containing extracted objects, whereby the extraction of said extracted objects by the method is automatic, stable and robust, and whereby no advance knowledge of the video sequences is needed to achieve the extraction.
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Specification