The HIS doesn't document the format of the thumbnail downloaded in the
getImageData CDP command.  I've more or less figured out (at least
well enough to get a recognizeable thumbnail image) the format of the
data.  I'm documenting it here until I get a definitive answer from
Kodak or Flashpoint. --jct

Header:

  UInteger: thumbnail length in bytes, not counting header.
  UInteger: thumbnail width in pixels
  UInteger: thumbnail height in pixels
  UInteger: unknown.

Data, (width * height) / 2 copies of:

  UByte: Cb component
  UByte: Y component
  UByte: Cr component
  UByte: unknown (padding?, grayscale?)
