>Tore,
>
>... and BMP files begin with "BM".
>
>Thanks for the JPG, GIF, and PNG file headers.
>
>Does anyone know if there's a consistent file header for WMF, EMF, TIF formats?
>
>Malcolm

As far as I could find out with a hex editor:
EMF: substr(yourfile,42,3)='EMF'
TIF: starts with 4D-4D-00-2A (hex()
WMF: starts with D7-CD-C6-9A (hex()javascript:MessageSubmit()