Patent ID: 7317407

Claim:
A lossless coding method for a signal in a floating-point format, comprising: (a) a step of converting a first signal sample sequence in the floating-point format into a second signal sample sequence in an integer format; (b) a step of losslessly compressing said second signal sample sequence in the integer format to produce a first code sequence; (c) a step of producing a difference signal in the floating-point format that corresponds to the difference between said second signal sample sequence in the integer format and said first signal sample sequence in the floating-point format; (d) a step of determining which coding processing is of higher compression efficiency, a first coding processing that codes a bit sequence of digits capable of assuming non-zero values in each of samples of said difference signal in the floating-point format, the digits being determined by the absolute value of the corresponding sample in said second signal sample sequence in the integer format, or a second coding processing that codes all digits of said difference signal; and (e) a step of coding said difference signal by said first coding processing to produce a second code sequence if the result of said determination indicates said first coding processing, or coding said difference signal by said second coding processing to produce a second code sequence if the result of said determination indicates said second coding processing.