Quality Issues for Compression of Hyperspectral Imagery Through Spectrally Adaptive DPCM

To meet quality issues of hyperspectral imaging, differential pulse code modulation (DPCM) is usually employed for either lossless or near-lossless data compression, i.e., the decompressed data have a user-defined maximum absolute error, being zero in the lossless case. Lossless compression thoroughly preserves the information of the data but allows a moderate decrement in transmission bit rate. Lossless compression ratios attained even by the most advanced schemes are not very high and usually lower than four. If strictly lossless techniques are not employed, a certain amount of information of the data will be lost. However, such an information may be partly due to random fluctuations of the instrumental noise. The rationale that compression-induced distortion is more tolerable, i.e., less harmful, in those bands, in which the noise is higher, and vice-versa, constitutes the virtually lossless paradigm.