Two layer video signal coding
First Claim
1. A method of coding a video signal for transmission, comprising the steps of:
- coding data representing the video signal by a base layer coding operation which includes a base layer quantization step size to provide coded video data for transmission;
deriving inverse-coded video data by carrying out an inverse base layer coding operation on the coded video data;
deriving difference data from the data representing the video signal and the inverse-coded video data; and
coding the difference data by an enhancement layer coding operation;
characterised in that the difference data is coded only when the energy of the difference data exceeds a variable threshold, the threshold being inversely proportional to the base layer quantization step size.
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Abstract
A method of coding a video signal for transmission includes the steps of coding data representing the video signal by a base layer coding operation which includes base layer quantizer having a base layer quantization step size to provide coded video data for transmission; deriving inverse-coded video data by carrying out an inverse base layer coding operation on the coded video data; deriving difference data from the data representing the video signal and the inverse coded video data; and coding the difference data by an enhancement layer coding operation only when the energy of the difference data exceeds a variable threshold, the threshold being inversely proportional to the base layer quantization step size.
85 Citations
7 Claims
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1. A method of coding a video signal for transmission, comprising the steps of:
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coding data representing the video signal by a base layer coding operation which includes a base layer quantization step size to provide coded video data for transmission; deriving inverse-coded video data by carrying out an inverse base layer coding operation on the coded video data; deriving difference data from the data representing the video signal and the inverse-coded video data; and coding the difference data by an enhancement layer coding operation; characterised in that the difference data is coded only when the energy of the difference data exceeds a variable threshold, the threshold being inversely proportional to the base layer quantization step size. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An apparatus for encoding a video signal for transmission, comprising:
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means for coding data representing the video signal by a base layer coding operation which includes a base layer quantizer having a base layer quantization step size to provide coded video data for transmission; means for deriving inverse-coded video data by carrying out an inverse base layer coding operation on the coded video data; means for deriving difference data from the data representing the video signal and the inverse-coded video data; and means for coding the difference data by an enhancement layer coding operation; characterised in that the means for coding the difference data operates only when the energy of the difference data exceeds a variable threshold, the threshold being inversely proportional to the base layer quantization step size.
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Specification