Why does IE7 specify a mime-type of image/pjpeg rather than just image/jpeg?

Question

When uploading a file (jpeg) via a form in IE7 I am seeing a mime-type of \"image/pjpeg\" instead of \"image/jpeg\" (as I see in Firefox or similar). It\'s easy enough to work

Answer 1

Because Microsoft likes to violate standards. There's no such MIME type as image/pjpeg. See for yourself: http://www.iana.org/assignments/media-types/media-types.xhtml#image

The correct MIME type for JPEG is image/jpeg, progressive or not.