Extracting the payload of a JPEG marker

[PixelDoctor]

I have a JPEG file from a custom application that puts a proprietary binary blob in an APP3 marker. Is there a way by which I can exiftool to extract that marker payload?

I tried exiftool -G -s -U -v my_image.jpg, which shows that it's present with the right size:

JPEG APP3 (345 bytes):
  Warning = [minor] Unknown APP3 segment

I just need to have it dump it to stdout (as binary) so I can pipe it to a file for downstream processing.

Thanks!

[Phil Harvey]

Adding -v4 should show you the contents in hex, but there is currently no way to dump this in binary.

- Phil

[PixelDoctor]

Cool, that works. Alas, I'll whip up a C program to actually dump the payload in binary. Thanks Phil!