Use this site, I just had to figure this out myself. I had to convert my photo, so you may need to use cloudconvert too. Actually, this type of thing would be a good pin topic. My steps were to email the photo to myself, convert the photo to the appropriate file type (JPG?), and then create the URL in the IM.GE site.
IM.GE - Free Image Hosting - Upload Image & Share
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