Filtering DEMs

Filtering digital elevation models (DEMs) calculates new z-values for the pixels in the DEM by using an average of the values from the pixels around it. This is important when merging DEMs to smooth the edges where two DEMS come together.

Learn more about how filter works


You must have the ArcGIS Spatial Analyst extension enabled to perform this task. For information on enabling the ArcGIS Spatial Analyst extension, see Enabling the Spatial Analyst extension.

  1. Start ArcMap.
  2. Load the DEMs files you want to use to create contours in ArcMap.
  3. On the main menu, click Customize > Toolbars > Production Contouring.
  4. Click the Merge and Filter DEMs button Merge and Filter DEMs on the Production Contouring toolbar.

    The Merge and Filter DEMs dialog box appears.

    Merge and Filter DEMs dialog box
  5. Choose Filter Individual Layers in the Operation area.

    You can merge the raster layers by choosing the Merge and Filter Result option in the Operation area.

  6. Click the Open button Open next to the Merging/Filtering Output DEM Workspace field.

    The Choose DEMs Folder dialog box appears.

  7. Navigate to a current raster folder.

    The folder you choose must be a preexisting DEM workspace.

  8. Click Open.
  9. Type a name for the filtered file in the Filtered Output Name text box.
  10. Check the Apply Focal Majority check box.
  11. Type a quantity in the Number of Times to Apply Focal Mean text box.

    The value can be a number between 1 and 5.

  12. Click OK.