Optimize pdf files

Tuprules.tup

@@ -17,6 +17,7 @@ HTML_TEMPLATE = main.html
 !png = |> convert %f %o |> %B.png
 !compress_png = |> zopflipng %f %o |>
 !compress_jpg = |> cjpeg -quality 80 -progressive -outfile %o %f |>
+!compress_pdf = |> ps2pdf %f %o |>
 
 JPG_OPT = -quality 80 -strip -interlace Plane
 !blur_mini = |> convert %f -resize 400x400 -blur 0x8 $(JPG_OPT) %o |> blur_mini.jpg

files/Tupfile

@@ -1 +1 @@
-:foreach *.pdf |> ps2pdf %f %o |> %g_opt.pdf
+:foreach *.pdf |> !tup_preserve |>