Removing the background area of a raster layer using the Unique Values renderer
- In ArcMap, in the table of contents, right-click the raster layer from which you want to remove the background and click Properties.
- Click the Symbology tab and click Unique Values from the Show list.
- Click the symbol that represents background (usually with a value of zero).
- Click Remove.
The background cells are removed and, therefore, will not be displayed. To put them back, click Add All Values.
- Click OK.
You can choose to hide the background color by displaying it transparently. Right-click the background color in the table of contents and choose No Color.