image to pdf

I really can't handle ImageMagick when it comes to pdf files. It creates such huge files they are completely useless.

I tried out another way: pbm -> ps -> pdf:

first I ImageMagick convert pbm-s:
mogrify -format ps -density 300x300 *.pbm
then put them into ps2pdf:
#!/bin/bash
lista=(`find -iname '*.ps' | sort`)
for i in "${lista[@]}"
do
ps2pdf -r300 -g1880x2688 $i $i.pdf
done
and bind them:
pdfjoin *.pdf --outfile output.pdf

It worked brilliantly. This way my pdf is 8 times smaller then my original pdf, and it's only 1.5 times bigger then the djvu I made from the same images.

Djvu was made directly from pbm files, converted with cjb2 and binded with djvm. No special option was used.