A MIFF file consists of two sections. The headers consist of ISO-8859-1 encoded bytes, each with pairs consisting of key=value. Keys include background-color, depth, compression rows, units, and custom key/value pairs. The latter can include things like copyright or comment. The list is terminated with a NULL character.
The next section contains the binary image data. The exact format is defined by the class header. Usually it is RGBA or CMYK.