问题
Do you know if I can send to browser the MIME type image/jpeg even if the image I am outputting is image/Pjpeg? Or are they different format?
回答1:
I believe most browsers wouldn't mind, except Internet Explorer which treats pjpeg files differently.
According to this conversation, you should accept both image/pjpeg and image/jpeg from your clients as upload mime types, but force the image/jpeg when serving downloads.
来源：https://stackoverflow.com/questions/5147049/image-pjpeg-and-image-jpeg