It must have been. I opened up the image in Fireworks and re-exported it as a jpg and it worked fine. Someone on our marketing team sent me this image. It had a .jpg extension but didn't work. Any idea why?
You can always use isImageFile to see if the file is a readable image.
Its not to do with progressive JPG; image functions handle those just fine.
While I'm still uncertail as to the precise cause of the problem, this fix seems to be working for me:
<cffile action = "readbinary" file="d:\inetpub\wwwroot\test.jpeg" variable="tmpBin">
<cfimage action="READ" name="tmpImage" source="#tmpBin#">
Read the image as a binary then process the binary.