How to remove watermark from pdf using pdftk?

Question

I need to remove some stupid email watermark that expands across all pages of a public domain book. I looked at pdftk man page and some examples but still can not figure out how to remove the watermarks. I appreciate your hints.

Solution 1

very simply task to perform:

use sed:

 sed -e "s/watermarktextstring/ /g" <input.pdf >unwatermarked.pdf

but, after, be sure to repair resulting output pdf

pdftk unwatermarked.pdf output fixed.pdf && mv fixed.pdf unwatermarked.pdf

all into one command:

 sed -e "s/watermarktextstring/ /g" <input.pdf >unwatermarked.pdf && pdftk unwatermarked.pdf output fixed.pdf && mv fixed.pdf unwatermarked.pdf

text watermarks are nothing else than a text between two tags inside the pdf compressed code

Solution 2

Just a little add-on to Dingo's answer as it did not work for me:

I had to first uncompress the PDF document in order to be able to find the watermark and replace it with sed. The first step involves uncompressing the PDF document using pdftk:

pdftk original.pdf output uncompressed.pdf uncompress 

now, the uncompressed.pdf can be used as in Dingo's answer:

sed -e "s/watermarktextstring/ /" uncompressed.pdf > unwatermarked.pdf

I then repaired and recompressed the document:

pdftk unwatermarked.pdf output fixed.pdf compress

Comments

[hnns]

Fantastic! worked like a charm. please just rename the email address to a fictitious one. I don't want the guy how spoiled the book be targeted by spammers. Specially as he is probably the one who has made the pdf. Many thanks.

[Admin]

done! Changed specific string with a generic string

[425nesp]

Does anyone know how to modify this solution to get rid of a link watermark? I got rid of the text, but there's still a small square left where the text used to be.

[johndodo]

You are a life-saver! Thank you!!! :)

[qed]

This is really awesome!

[Alexander Garden]

I took this process, made it slightly fancier, and wrapped it up in a Python script. It is on github here.

[8bitjunkie]

@Alexander Garden It doesn't work, TypeError: str() takes at most 1 argument (2 given) when used following the usage advice given

[Alexander Garden]

@8bitjunkie Can you open a github issue with a full stack trace?

[gdecaso]

I was having issues with this approach due to pdftk not being able to open the unwatermarked.pdf file. What did the trick was to replace the watermarktextstring via sed using a replacement string which was just N number of space characters where N is the length of the original watermark. In other words, make sure your uncompressed.pdf and unwatermarked.pdf have the same length

[David Foerster]

+1 I used the sed command /watermarktextstring/d instead because my water mark string was interlaced with formatting instructions or typographic hints or something like that.

[Karlo]

Is this a general solution? What is www.it-ebooks.info?

[Karlo]

@Philippe The second command gives an error: "sed: RE error: illegal byte sequence", what should I do?

[Cerin]

pdftk crashed when I ran this.

[akhan]

Since qpdf is the default tool on many distros, here is how to uncompress using qpdf.

[Clain Dsilva]

@Philippe any idea on how to batch remove watermark?

[Clain Dsilva]

@Dingo how do batch process it? I mean multiple files

[Dingo]

Multiple files having same text string to replace or different strings for each file?

[fccoelho]

Didn't work to remove watermark added by Master PDF Editor.

[graffe]

Genius :) Thank you.