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Three-dimensional wavelet-based scalable video compression

  • US 20040028138A1
  • Filed: 04/23/2003
  • Published: 02/12/2004
  • Est. Priority Date: 10/24/2000
  • Status: Active Grant
First Claim
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1. A method of encoding an input video signal comprising a group of video frames for communication over a computer network, the method comprising the steps of:

  • i) applying a two-level temporal decomposition using a wavelet to said group of frames to produce a plurality of temporal subbands;

    ii) applying a spatial decomposition to each said temporal subband to produce a plurality of spatio-temporal subbands;

    iii) quantizing the coefficients of said spatio-temporal subbands with a uniform scalar quantizer to produce a significance map; and

    iv) run-length and adaptive arithmetic coding of said signal by a) encoding the significance map through a combination of run-length and adaptive arithmetic coding by;

    A) coding run-length codewords using N-ary adaptive arithmetic coding, where N is the maximum run-length previously observed in coding the significance map; and

    B) encoding the current run-length codeword using one of a specified plurality of probability models, the probability model being selected by a rule which selects a probability model according to the previous run-length codeword;

    b) encoding the signs of all significant coefficients using the number of significant coefficients in a four pixel neighborhood as context; and

    c) encoding the magnitudes of significant coefficients, in bit-plane order starting with the most significant bit-plane, using the number of significant coefficients in a four pixel neighborhood as context.

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