Compressing method and device, decompression method and device, compression/decompression system, and recorded medium

摘要

There are provided: an offset adding section 3 for converting signed digital data to unsigned digital data by adding an offset value to signed digital data to be compressed, a rounding section 5 for reducing the number of bits per word by performing a rounding operation of a lower-order bit on the unsigned digital data, a timing synthesizer 6 and a compressing section 7 for sampling the digital data undergoing a rounding operation at a time interval of a point where a differential value varies in polarity and for obtaining as compressed data a pair of a discrete amplitude data value on each sample point and a timing data value indicative of a time interval between sample points. When a signal is compressed and expanded on a time base, the operation can be performed on the time base without frequency conversion.