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.

Steps:

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.