Does anyone know if it is possible to use a hidden form field with a value that is the binary of an image?

Basically my company wants an e-mail signature with our company logo image as part of the signature at the bottom of our e-mails. It's shocking how complicated this gets. You generally have two options, use this crazy DLL to read the image file from an attachment that is always sent with the e-mail. Alternatively you can host the image on a web server and reference it with a standard HTML image tag, but that of course will only work when you are online, and people use local e-mail clients like Thunderbird, Outlook Express and Outlook so that doesn't seem like a great option either.

My idea is that you should be able to put in a hidden form field value with the binary string as it's value, and have a javascript function that reads that value and if the e-mail client allows javascript, then output the image, else, don't output the image.

Can this be done?