I tried to add things like :

use utf8;
use open ':std' => ':utf8';
utf8::encode($string);
[download]

with no luck

Don't just randomly add stuff that is related to the problem, but try to understand how encodings are handled in Perl, and act accordingly.

If PDF::EasyPDF follows the usually model of receiving decoded text strings, and your strings come from literals in the source file, a simple use utf8: should be enough.

But this paragraph in the documentation is somewhat discouraging:

BUGS

None known, but the methods do relatively little sanity checking, and there is absolutely no encoding yet for text (so it's probably impossible to print parentheses, for example).

So if you can't even print all ASCII characters, I'd be surprised if it worked reliably for non-ASCII characters.