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.
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.
Right-click on the colormap image > Save As Layer File.
Perform the Extract by Mask on the colormap image.
The output raster is grayscale with stretched symbology. Right-click the new Output Raster > Properties > Symbology tab. Select Unique Values and click Import.
Browse to and select the layer file created previously. The colors are updated accordingly.