MRF (Monochrome Recursive Format)
MRF (Monochrome Recursive Format) is a bi-level raster image file format developed by Russell Marks.
MRF images are always compressed. The compression scheme is somewhat unusual, and involves recursively subdividing tiles until each is a single color.
Some sources say that the MR in MRF stands for Marks Russel (i.e., the developer's name backwards and misspelled), but the pbmtomrf-1.0 distribution makes it clear that it stands for Mono Recursive or Monochrome Recursive.
Files have a 13-byte header, followed by the compressed image data.
Files begin with a 4-byte ASCII signature: "