JPEGsnoop
Calvin Hass
JPEGsnoop is a free, portable detailed image decoder that examines any file type containing JPEG compressed images and reports a wealth of hidden information. It can even be used to determine the source of an image or whether it has been edited. Can open .JPG, .THM, .AVI, .DNG, .PDF and extract embedded JPEG files. JPEGsnoop reports countless details, including image quality, EXIF / IPTC metadata, or huffman table decode.