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.

Disambiguation
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.

Format
Files have a 13-byte header, followed by the compressed image data.

Identification
Files begin with a 4-byte ASCII signature: " ".

Specifications

 * MRF format

Software

 * Netpbm: pbmtomrf, mrftopbm
 * pbmtomrf-1.0.tar.gz
 * XnView