Low-Complexity Lossless Low-Complexity Lossless Compression of Hyperspectral Compression of Hyperspectral Imagery via Linear PredictionImagery via Linear Prediction

By:By: Fei Nan Fei Nan& Hani Saad& Hani Saad

Presented to:Presented to: Dr. Donald Adjeroh Dr. Donald Adjeroh

Hyperspectral Image CompressionHyperspectral Image Compression 22

IndexIndex Hyperspectral Images, what are they?Hyperspectral Images, what are they? Remote Sensors and Low-complexity Remote Sensors and Low-complexity

Image CompressionImage Compression Linear Prediction (LP)Linear Prediction (LP) Spectral Oriented Least Squares (SLSQ)Spectral Oriented Least Squares (SLSQ) LP ImplementationLP Implementation SLSQ ImplementationSLSQ Implementation Experimental ResultsExperimental Results ImprovementsImprovements ReferencesReferences

Hyperspectral Image CompressionHyperspectral Image Compression 33

Hyperspectral ImagesHyperspectral Images

High-definition electro-optic High-definition electro-optic imagesimages

Used in surveillance, geology, Used in surveillance, geology, environmental monitoring, and environmental monitoring, and meteorologymeteorology

224 contiguous bands224 contiguous bands 3 or more consecutive 3 or more consecutive

scenesscenes

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Remote Sensors & Low-complexity Remote Sensors & Low-complexity Image CompressionImage Compression

Hyperspectral sensors measure hundreds of wavelengths

Airborne vs. Satellite Sensors Why low-complexity compression?

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Linear Prediction (LP)Linear Prediction (LP)

Spatial correlationSpatial correlation Spectral correlationSpectral correlation LPLP

• Interband linear prediction for interband Interband linear prediction for interband codingcoding

• Standard median predicton for Standard median predicton for intraband codingintraband coding

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Linear Prediction cont’dLinear Prediction cont’d

Standard median predictonStandard median predicton• Used for intraband codingUsed for intraband coding

Xi,j,kXi-1,j,k

Xi,j-1,kXi-1,j-1,k

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Linear Prediction cont’dLinear Prediction cont’d

Interband linear predictionInterband linear prediction• Used for interband codingUsed for interband coding

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Spectral Oriented Least Squares Spectral Oriented Least Squares (SLSQ)(SLSQ)

Prediction defined in two different Prediction defined in two different enumerations for pixel:enumerations for pixel:

1.1. Intraband enumerationIntraband enumeration

2.2. Interband enumerationInterband enumeration

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LP ImplementationLP Implementation

The first 2 conds apply to The first 2 conds apply to Interband.Interband. 2 2ndnd cond can be skip when T=cond can be skip when T=œœ, given T gives , given T gives best performance.best performance.

The 3The 3rdrd cond applies to cond applies to Intraband(IB). Intraband(IB).

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SLSQ ImplementationSLSQ Implementation

The distance of Interband and intraband are defined.

The Predictor Error

Matrix C and Matrix X

The simplified form when we assigned M=4 and N=1.

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Experimental ResultsExperimental Results

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Experimental Results cont’dExperimental Results cont’d

128x128x224128x128x224LPLP SLSQSLSQ

CupriteCuprite 1.9181.918 2.4252.425

JasperJasper 1.8501.850 2.3642.364

Low Low AltitudeAltitude

1.7081.708 2.1312.131

Lunar Lunar LakeLake

2.0652.065 2.3902.390

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ImprovementsImprovements

Using M=5 vs. M=4Using M=5 vs. M=4 Keeping N=1Keeping N=1

Future Future improvements can improvements can include look-ahead include look-ahead predictionprediction

SLSQ2SLSQ2 SLSQ1SLSQ1CupriteCuprite 2.4432.443 2.4252.425

JasperJasper 2.3582.358 2.3642.364

Low Low AltitudeAltitude

2.1292.129 2.1312.131

Lunar Lunar LakeLake

2.4132.413 2.3902.390

AverageAverage 2.332.33 2.322.32

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ReferencesReferences Randall B. Smith, Ph.D., 17 September 2001. Randall B. Smith, Ph.D., 17 September 2001.

MicroImages, Inc. Introduction to Hyperspectral MicroImages, Inc. Introduction to Hyperspectral Imaging with TNTmips. Imaging with TNTmips. www.microimages.comwww.microimages.com

Peg Shippert, Ph.D., Earth Science Applications Peg Shippert, Ph.D., Earth Science Applications Specialist Research Systems, Inc. Introduction Specialist Research Systems, Inc. Introduction to Hyperspectral Image Analysis.to Hyperspectral Image Analysis.

Suresh Subramanian,, Nahum Gat, Alan Suresh Subramanian,, Nahum Gat, Alan Ratcliff , Michael Eismann. Real-time Ratcliff , Michael Eismann. Real-time Hyperspectral Data Compression Using Principal Hyperspectral Data Compression Using Principal Components TransformationComponents Transformation