Signal compression using index mapping technique for the sharing of quantization tables

DC
  • US 5,920,853 A
  • Filed: 08/23/1996
  • Issued: 07/06/1999
  • Est. Priority Date: 08/23/1996
  • Status: Expired due to Term
First Claim
Patent Images

1. A system for coding and decoding feature vectors of a signal transmitted through a communications channel, comprising a coder and a decoder, wherein:

  • a) the coder comprises;

    extraction means for extracting an input feature vector from the signal;

    coder memory means for storing one pre-designed VQ table for the coder, the coder memory means using a set of primary indices to address entries within the pre-designed VQ table;

    coder mapping unit for mapping indices from a set of fixed length secondary indices to the set of primary indices, the set of secondary indices corresponding to one pre-selected subset of the pre-designed VQ table;

    search means coupled to the coder mapping unit for searching for one index out of the set of secondary indices, wherein the one index from the set of secondary indices corresponds to one index from the set of primary indices which corresponds to an entry in the coder memory means, wherein the entry in the coder memory means which best represents the input feature vector according to predetermined criteria;

    b) the decoder comprises;

    decoder memory means for storing the same at least one pre-designed VQ table as stored by the coder memory means, the decoder memory means also using the set of primary indices to address entries within the pre-designed VQ table;

    decoder mapping unit for mapping the one index from the set of secondary indices to one index from the set of primary indices;

    retrieval means for retrieving an entry from the decoder memory means by mapping the one index from the set of primary indices as mapped by the decoder mapping unit to one entry from the decoder memory means, wherein the entry best represents the input feature vector.

View all claims
    ×
    ×

    Thank you for your feedback

    ×
    ×