I'm looking for the best tool out there to extract any and all metadata embedded within the most popular image file formats (JPEG and PNG specifically). I would like to know about whatever is in there (XMP, Exif, IPTC/IIM, etc.). Ideally I am looking for an all-in-one solution that I can run from a command line, but am interested to hear about any other tools in this area that are of value.
I have found the following, each with advantages/disadvantages:
ExifTool is good, but the output is a little more roughshod that I would like.DumpImage from the Metadata Working Group has good formatting of the metadata it does find, but doesn't support PNG.I have recently released Binspector, the tool I ended up writing to answer this question to my own satisfaction. The basic premise of the tool is that it takes a format grammar and uses it to analyze a binary file. As long as the format grammar and the binary file are well-formed, one can inspect and analyze innumerable binary files and formats.
Code is hosted on GitHub, and a blog for the tool is here. (The overview post for the tool is here.)