Use Class Statistics compute statistics on a raster.

You can also write a script to compute statistics using the ClassStatistics task.

  1. From the Toolbox, select Classification > Post Classification > Class Statistics. The Class Statistics dialog appears.
  2. Select an Input Raster to use for statistics generation. Perform any optional spatial subsetting, then click OK.
  3. Select an Input Classification Raster to use for statistics generation. Perform any optional spatial subsetting, then click OK.
  4. Specify a Classes. This field represents the structuring element used to expand shapes contained in the input image. An array size of 3x3 and element values of 1 are used unless otherwise specified.
  5. For Compute Covariance, select Yes if you want to to compute covariance matrix, eigenvectors, eigenvalues, and correlation.
  6. For Compute Histograms, select Yes if you want to to compute histograms.
  7. Use Output Report URI to specify an output location and filename for the text file that will contain the statistics.
  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. To reuse these task settings in future ENVI sessions, save them to a file. Click the down arrow next to the OK button 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.

  10. To run the process in the background, click the down arrow next to the OK button 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.

  11. Click OK.