Decoding of a quantized digital signal
AssigneeCanon Kabushiki Kaisha
InventorFélix Henry
Life of this patent
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Abstract
A method and apparatus for decoding a quantized digital signal. Quantization symbols are read and an experimental distribution of the quantization symbols is constructed. An experimental distribution is approximated by means of a continuous distribution model which passes through values of the experimental distribution. A dequantization vector, for at least one quantization cell, equal to the center of mass of the points of the quantization cell weighted by the values of the restricted continuous distribution is calculated. The dequantization vectors associated respectively with the quantization symbols are then stored for use in decoding.
Claims15
A method of decoding a coded digital signal, the coded signal being quantized by means of quantization symbols associated respectively with quantization cells, said method comprising the steps of:
- reading the quantization symbols;
- constructing an experimental distribution of the quantization symbols on the quantization cells by calculating the number of occurrences of the quantization symbols in the coded signal;
- approximating the experimental distribution by means of a continuous distribution model the continuous distribution model passing through values of the experimental distribution
- calculating, for at least one quantization cell, a dequantization vector equal to a center of mass of the points of the quantization cell weighted by values of the continuous distribution restricted to the quantization cell;
- storing the dequantization vectors associated respectively with the quantization symbols;
- and
- dequantizing the coded signal, representing each vector of the signal by means of a dequantization vector associated with the quantization signal received.
A device for decoding a coded digital signal, the coded signal being quantized by means of quantization symbols associated respectively with quantization cells, comprising:
- means for storing the a form of the quantization cells;
- means for reading the quantization symbols;
- means for constructing an experimental distribution of the quantization symbols on the quantization cells by calculating a number of occurrences of the quantization symbols in the coded signal;
- means for approximating the experimental distribution (Oi) by means of a continuous distribution model, the continuous distribution model passing through values of the experimental distribution;
- means for calculating a dequantization vector equal to a center of mass of points of the quantization cell weighted by the values of the continuous distribution restricted to the quantization cell (Ci);
- means for storing the dequantization vectors associated respectively with the quantization symbols;
- and
- means for dequantizing the coded signal, adapted to represent each vector of the signal by means of a dequantization vector associated with the quantization signal received.
Dependencies are inferred from the claim text.