Avis à tous les limiers : recherche un bon compresseur PDF, efficace, portable, et réellement freeware...

Outils en ligne s'abstenir.

je connais PDFTK (version DOS )qui le fait. Jamais utilisé mais c'est dans les options :

pdftk 1.12 a Handy Tool for Manipulating PDF Documents
Copyright (C) 2003-04, Sid Steward - Please Visit: www.pdftk.com
This is free software; see the source code for copying conditions. There is
NO warranty, not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SYNOPSIS
pdftk <input PDF files | - | PROMPT>
[input_pw <input PDF owner passwords | PROMPT>]
[<operation> <operation arguments>]
[output <output filename | - | PROMPT>]
[encrypt_40bit | encrypt_128bit]
[allow <permissions>]
[owner_pw <owner password | PROMPT>]
[user_pw <user password | PROMPT>]
[flatten] [compress | uncompress]
[verbose] [dont_ask | do_ask]
Where:
<operation> may be empty, or:
[cat | attach_files | unpack_files | burst |
fill_form | background |
dump_data | dump_data_fields | update_info]

la version est plus forcément dispo sur la toile

Chris