Spectral Information Divergence Classification (SID) is a spectral classification method that uses a divergence measure to match pixels to reference spectra. The smaller the divergence, the more likely the pixels are similar. Pixels with a measurement greater than the specified maximum divergence threshold are not classified.

Reference: Du, H., C.-I. Chang, H. Ren, F. M. D’Amico, and J. O. Jensen, J. "New Hyperspectral Discrimination Measure for Spectral Characterization." Optical Engineering 43, No. 8 (2004): 1777-1786.

You can also write a script to perform Spectral Information Divergence classification using the SpectralInformationDivergenceClassification task.

  1. From the Toolbox, select Classification > Supervised Classification > Spectral Information Divergence Classification. The Spectral Information Divergence Classification dialog appears.
  2. Select an Input Raster and perform optional spatial and spectral subsetting, and/or masking.
  3. Select the Input ROIs file that represents the classes. Statistics from the ROIs are used as input to the Adaptive Coherence Estimator calculation.
  4. In the Threshold field, specify a maximum value, or array of maximum values (one for each class), for each class that is tested against its corresponding maximum spectral divergence. The default value is 0.05.
  5. Enter a filename and location for the Output Raster.
  6. Enable the Display result check box to display the output in the view when processing is complete. Otherwise, if the check box is disabled, the result can be loaded from the Data Manager.
  7. Enter a filename and location for the Output Rule Raster.
  8. Enable the Display result check box to display the output in the view when processing is complete. Otherwise, if the check box is disabled, the result can be loaded from the Data Manager.

  9. Enable the Preview check box to see a preview of the settings before you click OK to process the data. The preview is calculated only on the area in the view and uses the resolution level at which you are viewing the image. See Preview for details on the results. To preview a different area in your image, pan and zoom to the area of interest and re-enable the Preview option.

  10. To see a model-based version of this tool that shows how the tool is constructed from individual tasks, click Open in Modeler.

  11. To reuse these task settings in future ENVI sessions, save them to a file. Click the down arrow and select Save Parameter Values, then specify the location and filename to save to. Note that some parameter types, such as rasters, vectors, and ROIs, will not be saved with the file. To apply the saved task settings, click the down arrow and select Restore Parameter Values, then select the file where you previously stored your settings.

  12. To run the process in the background, click the down arrow and select Run Task in the Background. If an ENVI Server has been set up on the network, the Run Task on remote ENVI Server name is also available. The ENVI Server Job Console will show the progress of the job and will provide a link to display the result when processing is complete. See ENVI Servers for more information.

  13. Click OK.