Image Calibrator

Calibration of Spectral Imagery to Apparent Reflectance
Image calibration is an indispensable step when analyzing spectral data, particularly hyperspectral data. Uncalibrated image data contain spectral contributions due to atmospheric scattering and absorption as well as sensor effects. These contributions, together with illumination differences, distort the recorded material radiance spectra and limit the ability of most spectral processing algorithms to properly classify materials of interest.

Image Calibrator is a simple, robust tool for calibrating spectral imagery to apparent reflectance. The software is entirely automatic and entirely scene-based. You are not required to identify bright and dark pixels associated with known reflectance materials. Nor do you need to specify weather and atmospheric conditions together with relative solar position, like you do with most model-based approaches. Image Calibrator is extremely easy to use and it provides you with a calibration confidence figure of merit that lets you know when the calibration factors are accurate. No guesswork or iterative processing is involved.

Benefits
· Improves the visual clarity and contrast of your spectral imagery.
· Provides more reliable classification results, both in-scene and scene-to-scene.
· Enables you to apply library signatures to spectral imagery.
· Saves time overall, especially when calibrating several images.
· Requires no external information or ground truth.

Applications
· Material of Interest Classification
· Land Cover Classification
· Change Detection
· Quantitative Assessments
· Mineral Mapping

Key Features
· Accuracy comparable to other calibration techniques.
· Confidence value indicates when calibration is valid.
· Applicable to virtually any multispectral or hyperspectral imagery.
· Completely automated with minimal inputs.
· No user interaction is required.
· Entirely scene-based, no external information required.
· Spatially constant calibration for entire image.
· Reflectance image stored in 16-bit form for maximal reflectance resolution.
· Calibration factors available for use with IMAGINE Spectral Analysis