Is there a way to infer what image format a file is, without reading the entire file?

Question

Is there a good way to see what format an image is, without having to read the entire file into memory?

Obviously this would vary from format to format (I\'m particular

Answer 1

TIFFs will begin with either II or MM (Intel byte ordering or Motorolla).
The TIFF 6 specification can be downloaded here and isn't too hard to follow