Patent ID: 6539122
Filing Date: 2003-03-25
Classification: G06T

Abstract:
An apparatus for use in compressing hyperspectral imagery, said hyperspectral imagery including a sequence of images, said apparatus comprising:a differential pulse code modulation (DPCM) loop for processing at least two images to create an error image; a discrete wavelet transform (DWT) decomposition unit for decomposing said error image into a plurality of frequency subbands; and a trellis coded quantization (TCQ) encoder for quantizing information within said plurality of frequency subbands according to a plurality of discrete quantization levels to create a coded output signal; wherein said TCQ encoder includes a classification unit for classifying at least one block within each of said plurality of frequency subbands into one of a plurality of classes; said plurality of frequency subbands includes a first frequency subband that includes a plurality of blocks; said classification unit includes means for determining a first number of blocks in said first frequency subband that fall within a first class in said plurality of classes and a second number of blocks in said first frequency subband that fall within a second class in said plurality of classes; said classification unit includes means for adjusting said first number of blocks and said second number of blocks; said means for adjusting includes means for adjusting using a statistical criterion; and said statistical criterion includes a combination of a variance value for blocks that fall within said first class and a variance value for blocks that fall within said second class.