Does google index image filenames?

[smith33]

I know with their images.google.com service they index the actual image filename, but what about for regular web indexing?

So if the image is named:
ourcompany.jpg

"ourcompany" has a better chance of being indexed rather than:
logo.jpg

A quick test for the same keyword on images.google.com and google.com returned completely different sites/results, so I'm guessing the answer is no.

Does the same go for other file names like .php, .asp, .pdf, etc?

[smith33]

Can anyone confirm this? I can't find anything related. Thank you in advance!