ImageMagick supports many file formats. Listed here are a few of the more common ones (quoted from the README, but I've edited the descriptions in places). For information on most of the formats mentioned below and image file formats generally, see the O'Reilly book Encyclopedia of Graphics File Formats by James D. Murray & William vanRyper (ISBN: 1-56592-058-9).
AVS AVS X image file
YUV CCIR 601 4:1:1 file (see section on display)