I would like to perform a Tasseled Cap Transformation using the Raster Function Editor in ArcGIS 10.1 but I always receive an error message 'The function could not be inserted. The input or output arguments are invalid.' I downloaded my LANDSAT images from the platform Glovis and the metadata is stored in a .txt file. From what I understand, I need the proper metadata on the raster to be able to perform the function, but I don't know if it is possible. I have tried to input it using ArcCatalog, by importing the txt file on the raster, but it still does not work.