How To: Preserve colormap when performing an Extract By Mask


When performing an Extract By Mask on an image that has a colormap, the colormap is not retained for the new output. The instructions provided show how to retain the colormap colors for the new output.


  1. Right-click on the colormap image > Properties > Symbology tab. Change the symbology to Unique Values. The same colors that were represented by the colormap are now represented by unique values. Click OK.
  2. Right-click on the colormap image > Save As Layer File.
  3. Perform the Extract by Mask on the colormap image.
  4. The output raster is grayscale with stretched symbology. Right-click the new Output Raster > Properties > Symbology tab. Select Unique Values and click Import.
    [O-Image] Import
  5. Browse to and select the layer file created previously. The colors are updated accordingly.