Determining if file is valid image file

[Terry Reedy]

"Jarek Zgoda" <jzgoda at usun.pl> wrote in message 
news:f8tbd6$rnh$1 at nemesis.news.tpi.pl...
André napisa³(a):

>>>> Other than installing PIL, is there a "simple" way using Python only
>>>> to determine if a file is a valid image file?
[...]
> Be aware that broken images (i.e. partially downloaded) in many cases
> pass the imghdr.what() test.

To put it another way, the only way to determine whether a coded file is 
valid may be to decode it.  And even then, it may be corrupted in the sense 
that the decoded version may have artifacts not in the original.  I have 
seen the latter both in jpeg images and movie DVDs.

tjr