Using the Mask button on the Image Analysis window

The Mask button can be used with any raster, mosaic, or image service layer to create a hidden or masked area within the dataset. The masked area can be defined by the following:

• The data view extents
• A selected polygon graphic
• A selected polygon feature within a feature class layer

The masked area will appear transparent in the temporary layer.

1. To view the Image Analysis window in ArcMap, click Windows on the Main menu and click Image Analysis.
2. Click a layer in the Image Analysis window.
3. Optionally, select a polygon feature within a feature class layer or select a polygon graphic.
4. Click the Mask button .

   The masked output is added as a temporary raster layer to the table of contents. By default, the masked area is the area defined by the display view extents; otherwise, it is clipped to the selected feature or graphic.

   The Mask operation adds the Clip function to the raster layer.