width = 93
height = `perl -e 'print int($(width) * 0.46)'`
threshold = 0.78

spam_width = 98
spam_height = `perl -e 'print int($(spam_width) * 0.46)'`
spam_threshold = 0.75

target = fern.txt spam.txt

all: $(target)

fern.txt: fern.png Makefile pgmtotxt.pl trim_space.pl
	pngtopnm $< | pamscale -xsize=$(width) -ysize=$(height) | pamthreshold -simple -threshold=$(threshold) | pamtopnm | ppmtopgm | perl pgmtotxt.pl | perl trim_space.pl > $@
	perl freq.pl $@

spam.txt: spam.png Makefile pgmtotxt.pl trim_space.pl
	pngtopnm $< | pamscale -xsize=$(spam_width) -ysize=$(spam_height) | pamthreshold -simple -threshold=$(spam_threshold) | pamtopnm | ppmtopgm | perl pgmtotxt.pl | perl trim_space.pl > $@
	perl freq.pl $@

clean:
	-rm -f $(target)