Motion detection method and apparatus
First Claim
1. An apparatus for detecting motion in an input sequence of images, each image comprising a plurality of lines and each line comprising a plurality of pixels, said apparatus comprising:
- coding means for transforming values of pixels within at least one region of a current image to form a set of representation values at a plurality of different resolution levels;
means for comparing and iteratively determining a difference measure between said representation values for at least one of said plurality of different resolution levels and corresponding representation values from a stored set of representation values of a preceding image of said input sequence; and
difference means for determining a difference value from difference measures determined by said means for comparing, said difference value being generated by adding together difference measures for said plurality of resolution levels and indicating motion between said current image and said preceding image.
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Abstract
The present invention provides a method and apparatus for detecting motion in an input sequence of images. Each image comprises a number of lines and each line has a number of pixels. Values of a region of pixels of a current image are transformed to determine a set of representation values. The set of representation values are indicative of the region of pixels at a number of resolution levels. The set of representation values of the region of pixels of the current image are compared with a set of representation values of a corresponding region of pixels from a stored previous image. Based on the comparing step, a difference measure is determined between the region of pixels and the corresponding region of pixels that is indicative of the presence or absence of motion in the current image.
53 Citations
42 Claims
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1. An apparatus for detecting motion in an input sequence of images, each image comprising a plurality of lines and each line comprising a plurality of pixels, said apparatus comprising:
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coding means for transforming values of pixels within at least one region of a current image to form a set of representation values at a plurality of different resolution levels; means for comparing and iteratively determining a difference measure between said representation values for at least one of said plurality of different resolution levels and corresponding representation values from a stored set of representation values of a preceding image of said input sequence; and difference means for determining a difference value from difference measures determined by said means for comparing, said difference value being generated by adding together difference measures for said plurality of resolution levels and indicating motion between said current image and said preceding image. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for detecting motion in an input sequence of images, each image comprising a plurality of lines and each line comprising a plurality of pixels, said method comprising the steps of:
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transforming values of a region of pixels to determine a set of representation values, said set of representation values being indicative of the region of pixels at a plurality of resolution levels; comparing and iteratively determining a difference measure between the set of representation values of the region of pixels, of a current image, and a set of representation values of a corresponding region of pixels from a preceding image; and determining a difference value from difference measures obtained in said comparing step, said difference value being generated by adding together difference measures for said plurality of resolution levels and indicating motion between said current image and said preceding image. - View Dependent Claims (11, 12, 13, 14, 15)
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16. An apparatus for providing a display signal from an input sequence of images, said apparatus comprising:
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memory for storing image data; means for generating said display signal, wherein said generating means partially updates a display means for each region of a current image; and means for detecting motion in a current image of said input sequence, said detecting means being coupled to said memory and said generating means, said detecting means processing said current image as a plurality of blocks, said detecting means comprising; means for decomposing a block of pixel values of said current image to provide a set of representation coefficients at a plurality of different resolution levels; means for iteratively computing a difference for each resolution level between said set of representation coefficients of said current image and corresponding representation coefficients of a previous image stored in said memory; and means for measuring a block difference for said current block dependent on a plurality of differences, wherein said block difference measure indicates motion in said current block; wherein said generating means generates said display signal using said image data stored in said memory in response to said block difference measure, wherein said display signal contains a block of pixel values dependent upon said current block of pixel values. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A method for providing a display signal from an input sequence of images, said method comprising the steps of:
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detecting motion in a current image of said input sequence, wherein said current image is processed as a plurality of blocks, said detecting step further comprising the steps of; decomposing a block of pixel values of said current image to provide a set of representation coefficients at a plurality of different resolution levels; iteratively determining a difference measure for each resolution level between said set of representation coefficients of said current image and corresponding representation coefficients of a previous image stored in a memory; and measuring a block difference for said current block dependent on a plurality of differences, wherein said block difference measure indicates motion in said current block; and generating said display signal so as to partially update a display means using said image data stored in said memory in response to said block difference measure, wherein said display signal comprises a block of pixel values dependent upon said current block of pixel values. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
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38. A computer software system having a set of instructions for execution on processing means to detect motion between frames of an input video signal, said set of instructions formed into a plurality of process modules comprising:
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a transformation process for transforming a block of pixels of a current image frame to form a set of representation values at a plurality of different resolution levels; a comparison process for comparing and iteratively determining a difference measure between said set of representation values of the current image frame and a set of representation values of a corresponding block of pixels of a previous image frame; and a difference process for measuring a block difference between said block of said current image frame and said corresponding block of said previous image frame, utilizing said difference measure, said process including adding together difference measures for said plurality of resolution levels, wherein said block difference indicates motion in said current image frame. - View Dependent Claims (39, 40, 41, 42)
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Specification