libpuzzle: Libpuzzle (The Puzzle library)
libpuzzle:
libpuzzle: The  Puzzle  library  is  designed to  quickly find visually similar
libpuzzle: images (GIF, PNG, JPG), even if they have been resized, recompressed
libpuzzle: recolored or slightly modified.
libpuzzle: The library is free, lightweight yet very fast, configurable easy to
libpuzzle: use and it has been designed with security in mind.
libpuzzle: This is a C library, but is also comes with  a command-line tool and
libpuzzle: PHP bindings.
libpuzzle:
libpuzzle: