Minidjvu is a command line utility which encodes and decodes single
page black-and-white DjVu files, and can compress multiple pages,
taking advantage from similarities between pages.

Supported bitmap formats are PBM, Windows BMP, and TIFF (through
libtiff).

Minidjvu is based on DjVuLibre, which is the primary DjVu support
library.  Minidjvu is not going to support all DjVu functionality;
the idea is rather to take the black-and-white part (also called JB2)
and experiment with it.