Use Combine Classes to selectively merge classes in classified images.

Combining classes or removing the unclassified class effectively deletes those individual classes.

  1. From the Toolbox, select Classification > Post Classification > Combine Classes. The Combine Classes Input File dialog appears.
  2. Select a classified image and perform and any optional spatial subsetting, then click OK. The Combine Classes Parameters dialog appears.
  3. Select a class for input from the Input Classes list. The selected class name appears in the Input Class field.
  4. Select an output class by clicking on a class name in the Output Classes list.

  5. When both the input and output classes are selected, click Add Combination to finalize the selection. The new, combined class to create is shown in the Combined Classes list at the bottom of the dialog. For example, selecting region 1 as the input and region 3 as the output causes the string region 1 ‑> region 3 to appear in the Combined Classes list.

    To deselect combined classes, select the name in the Combined Classes list.

  6. Click OK. The Combine Classes Output dialog appears.
  7. Select output to File or Memory. ENVI adds the resulting output to the Layer Manager.