Comment by jmwilson

From the github repo, the site is a wrapper around exactly two shell commands. Instead of uploading your data to an untrusted site, you can run from the comfort and safety of your local computer:

  convert -density 150 input.pdf -colorspace gray -linear-stretch 3.5%x10% -blur 0x0.5 -attenuate 0.25 +noise Gaussian -rotate 0.5 temp.pdf
  gs -dSAFER -dBATCH -dNOPAUSE -dNOCACHE -sDEVICE=pdfwrite -sColorConversionStrategy=LeaveColorUnchanged dAutoFilterColorImages=true -dAutoFilterGrayImages=true -dDownsampleMonoImages=true -dDownsampleGrayImages=true -dDownsampleColorImages=true -sOutputFile=output.pdf temp.pdf