Sets the specific
image file format in which the image capture is to be stored (when "saved").
This format must be specified by a four-character code (FOURCC), for example,
MMOT or OS13, and must be one of the currently supported and installed MMIO
image file formats, or the device-specific format. This does not effect
the loading or restoring of images. It overwrites any previous file-format
value, such as that obtained through a LOAD operation.