Invisible Digital Watermarking (copyright striping) for content producers

Alphatec Eikonamark
Imperceptible copyright watermarking for audio
http://www.alphatecltd.com/watermarking/watermarking.html

Cinea Runningmarks
non-detectable indelible digital copyright watermarking
http://www.cinea.com/

DIGIMARC
Imperceptible / non-detectable watermarking and detection services
http://www.digimarc.com/tech/dwm.asp

Global File Registry
Content Protection and Tracking Service
http://www.globalfileregistry.com/solutions_contentowners.aspx

Philips Product Manager
non-detectable copyright watermarking
http://www.business-sites.philips.com/contentidentification/home/index.html

Thompson Nexguard
non-detectable copyright watermarking
http://www.thomson.net/EN/Home/Technology/technology_solutions/NexGuard.htm

Verance Consensus Secure Digital Music Initiative (SDMI)
non-detectable copyright watermarking
http://www.verance.com/

Verimatrix Content Authority System
Invisible watermarking and detection services
http://www.verimatrix.com/

Widevine Mensor
non-detectable forensic copyright watermarking
http://www.widevine.com/mensor.html