Lossless compression using the adaptive discrete cosine transform

This paper describes a technique using the adaptive discrete cosine transform for lossless waveform data compression. The technique is a variation on a two-stage lossless method that was developed by one of the authors. The earlier work employed an adaptive frequency sampling filter as part of an adaptive differential pulse code modulation-type (ADPCM) scheme to be applied to the output of a lossless successive difference operation to output a integer residual sequence for transmission, storage, or further encoding. The present work replaces the adaptive frequency sampling filter with an adaptive discrete cosine transform. The method remains lossless, unlike most ADPCM schemes.