Ray Rashif <schivmeis...@gmail.com> writes:

> On 8 August 2013 16:17, Rilke Rainer Michael <ri...@wiso.uni-koeln.de> wrote:
>> Hi List,
>> I want to export a lyx document to a pdf. However, I want also that once
>> reading the document it is impossible to copy and paste text from this pdf.
>> Do you have any idea, whether there is a workaround for lyx?

Just one word of caution: if you can see the text on screen, you can
extract it by taking a screenshot and using ocr (optical character
recognition) and nothing will stop you. So this just makes it slightly
more difficult to get the text.

As far as I remember, one can also convert the pdf to images, and do the
ocr automatically. Same with images - if they can be displayed, they can
be extracted.

> That is encryption. You have the choice of disabling printing as well.
> Converting to images, or rasterizing fonts, has the same effect as not
> allowing copies but greatly increases the file size. However, this is
> a standalone process, separate from LyX. I use PDFtk on GNU/Linux. [1]

pdftk is an excellent tool for doing this. You could even add it as a
copier into lyx to automatically encrypt - if you really want to.



> [1] http://www.pdflabs.com/docs/pdftk-cli-examples/
> --
> GPG/PGP ID: C0711BF1
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Rainer M. Krug

email: RMKrug<at>gmail<dot>com

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