Claims
- 1. 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.
- 2. 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 (σ12)p1(σ22)p1, where σ12 is a variance for blocks in said first class, σ22 is the variance for blocks in said second class, and p1 is a probability that a block in said first frequency subband belongs to said first class.
Parent Case Info
This application claims the benefit of U.S. Provisional Application No. 60/043,409, filed Apr. 4, 1997, which is hereby incorporated by reference in the present application.
US Referenced Citations (11)
Non-Patent Literature Citations (2)
Entry |
Sriram, P. Marcelin, M.W., “Imaging Coding Using Wavelet Transformation an Entropy-Constrained Trellis Coded Quantization,” IEEE Transactions on Image Processing, vol. 4, No. 6 Jun. 1995, pp. 725-733.* |
Ito et al, “A Wavelet Video Coder Using Entropy-Constrained Trellis Coded Quantization”, IEEE, pp. 598-601, Sep. 1994. |
Provisional Applications (1)
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Number |
Date |
Country |
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60/043409 |
Apr 1997 |
US |