Expand function

Available with Spatial Analyst license.


Expands specified zones of a raster by zones by a specified number of cells.

This is a global raster function.


The specified zone values are considered foreground zones, while the remaining zone values are considered background zones. With this tool, the foreground zones are allowed to expand into the background zones.

NoData cells are always considered background cells; therefore, neighboring cells of any value can expand into NoData cells. NoData cells will never expand into their neighbors.





The input raster for which the identified zones are to be expanded.

It must be of integer type.

Number Of Cells

The number of cells to expand by.

The value must be integer, and can be 1 or greater.

Zone Values


The list of zones to expand.

The zone values must be integer, and they can be in any order.

To specify multiple zones, use a space to separate the zone values.

Related topics

In this topic
  1. Overview
  2. Notes
  3. Parameters