Multiple-frame JPEG

[Captain_Goggles]

Ok, this was really really bothering me, and I can't figure out how the guy did this. How is this image below possible?

http://img477.imageshack.us/img477/6604/s108333001060884ks.jpg

I mean, you can't just simply rename a file extension from a GIF to a JPEG.

[_Aerospace_Eng_]

But that appears to be what he did. To the browser the information for a gif is all still there (in the image itself) but the extension is not. Try opening the image in a graphics editor like photoshop or fireworks, you get an invalid format or some error. Change the extension to .gif and it opens fine.

[hyperbole]

The browser looks at the mime type for the file and displays it based on that. It doesn't care what the extension is. You can rename a graphic to have the extension *.txt and the browser will still display it as a graphic if the mime type returned by the server is a graphic type.



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