Variable-rate multistage vector quantization of multispectral imagery with greedy bit allocation
Smita Gupta, A. Gersho · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1993
Multispectral satellite images of the earth consist of sets of images obtained by sensing electromagnetic radiation in different spectral bands for each geographical region. We have applied a variable rate multistage vector quantizer for the compression of multispectral imagery. Spectral and spatial correlation are simultaneously exploited by forming vectors from 3-dimensional data blocks. The wide variation in entropy across the data set is efficiently exploited by an adaptive bit allocation algorithm based on a greedy approach where the rate- distortion trade-off is locally optimized for each successive encoding stage. Simulation results on an image set acquired by a Thematic Mapper scanner are presented. A substantial improvement is obtained over prior vector quantization based coders for multispectral data compression.