Dewatering a pdf

There is this pdf ebook that I want to read, but it has a really annoying 'DRAFT' water mark on every page. I looked for an automatic way to remove the watermark and found a really handly superuser answer that completely covers it.

$ pdftk original.pdf output uncompressed.pdf uncompress 
$ sed -e "s/watermarktextstring/ /" uncompressed.pdf > unwatermarked.pdf
$ pdftk unwatermarked.pdf output fixed.pdf compress

Before I ran that I tried grepping through the pdf for the string 'DRAFT', now the pdf was compressed so I didn't find anything. I wanted to make sure the watermark was just a string so I extract just the first page with pdfseperate .

$ pdfseparate -f 1 -l 1 ipv6_for_ipv4_experts_en_a4.pdf out.pdf

I opened out.pdf with inkscape and played with editing the watermark, which was indeed just text. I then round tripped the pdf through pdftk and generated a watermark free pdf.

Reading: Gun Machine, The Difference Engine