PDF tips and tricks.
Removing password protection with Littlebirdy
$ git clone https://github.com/jakepetroules/littlebirdy
$ cd littlebirdy
$ ./littlebirdy /path/to/your.pdf
Compressing a PDF
Using GPL Ghostscript:
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf
Making a PDF look like a scanned document (Fedora)
First install ImageMagick:
dnf install imagemagick
Then:
convert -density 300 -colorspace Gray -depth 8 -quality 85 input.pdf output.pdf
Or:
convert -density 150 ORIGINAL.pdf -colorspace gray +noise Gaussian -rotate 0.5 -depth 2 SCANNED.pdf
Or:
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