I have a lot of .gif images which can be viewed by e.g. IrfanView, but not opened in photoshop. Photoshop says it can't interpret the file format module (I'm using it in German, so I don't know the exact english error message).
When opening the file in a text editor, it starts with gif89a. I guess it has something to do with this type, but how can I open/edit gif89 files in photoshop?
UPDATE:
I found out that the main difference between working and not working ones is, that the broken ones contain NETSCAPE2.0 in the first line in their source code where the others just have non-human-readable stuff. Both contain gif89a. Removing or editing the Netscape string breaks the file so it cannot be opened anymore in IrfanView.
save/save as...are grayed out, as well as most options underedit. Oh, this seems to be the case for everygifin IrfanView. And also the working files start withgif89a... – Cedric Reichenbach Aug 9 '12 at 8:54