Hi, You can start ENVI Classic from the IDL command line using a procedural statement as follows: IDL > envi However, you're restricted to using the ENVI Classic API for file management, display, and everything else. This API is described in the ENVI Classic help. Another option is to use the newer ENVI API (i.e., e = envi()) to open your rasters just like you have done, then use the ENVIRasterToFID routine to pass in a file reference to Classic in order to perform image processing routines. I'm not sure if this is your intent though. This process is described at http://www.exelisvis.com/...sitioningtoAPI.html. We are continually working on adding more functionality and image-processing routines to the ENVI API so that, in a future release, there won't be any more mixing Classic with ENVI programming. Hope this helps!