# -*- makefile -*-


# usage:  IN=`echo *.jpeg` make -f ~/mk/jpeg2djvu.mk -j 3




DJVUS=$(IN:.ppm=.djvu)

.PHONY: all

all: out.djvu

out.djvu: $(DJVUS)
	djvm -c out.djvu $(DJVUS)

# Ordinary dither gives large files.  What you really want is some
# adaptive threshold algorithm (pamthreshold).

DITHER=pamditherbw | pamtopnm
# DITHER=pgmtopbm -threshold 

# Dither to B&W.  This produces smaller files and seems ok for high res scans.
%.djvu: %.ppm
	cat $< | ppmtopgm | $(DITHER) | pbmtodjvurle | csepdjvu -d 300 - $@