I am trying to find trees of a single species (Cedar) in my orthophoto. My assumption is that the spectral bands of cedar trees are different to other vegetation (they definitely look different). I have created about 8 small training areas and united them in one class which I have saved as a signature file. I get two errors - one that the number of bands in my signature file is less than the number of bands in the raster, and the other is an error executing the grid expression.
Error 010108: The number of bands in the signature file is less than the number of bands in the raster
Error 010067: Error in executing grid expression
One factor that may be causing this is that my orthophoto is actually composed of a large amount of smaller tiles. I have created my training areas and signature file within one of the tiles but I want to apply the classification to about 30 of my tiles. I was getting an error message about extent so I changed the extent values to union of inputs in the environments options but I can't seem to get rid of the other error messages and I am clueless.