--- Start of Idrisi List message Hi, I want to perfom a Fourier Analysis on Landsat MSS and TM data so I can then perform a supervised classification to determine land cover, which Filter type would be best in FILTERFQ - Homomorphic or Butterworth or another? Could anybody please explain how to determine the value to use for the 'cut off frequency' option. Many thanks, Matt Matthew Linkie Durrell Institute of Conservation and Ecology Department of Anthropology University of Kent Canterbury CT2 7NS Tel: 01227 764000 Fax: 01227 827839 Website: http://www.sumatran-tiger.org.uk --- End of Idrisi List message IDRISI-L is an unmoderated list. As a service to list users, please post a summary of useful responses to your questions. To post a message to IDRISI-L, send it to [EMAIL PROTECTED] To subscribe to the list, send an email from the address to be subscribed to [EMAIL PROTECTED] with "subscribe" (without quotes) as the first line of the message body. To unsubscribe, do the same, only with "unsubscribe" as the first line of the message body.