Posted by Martin Heffels on 08/31/06 16:24

On 31 Aug 2006 08:55:19 -0700, "Andy Dingley" <dingbat@codesmiths.com>
wrote:

>I've heard it used, but rarely in this sense, and never in relation to
>web streaming. I think the term used to be used in TV. I've always
>called them watermarks too.

Watermark is a printing term, while videobug is used in, uhm well,
television (staion-id).

>Visible are good at discouraging blagging, invisible are good at
>proving things after you've caught the blagger. It's sometimes
>particularly useful if every copy gets a unique invisible watermark -
>then you can track just _who_ let their copy get copied.

Invisible watermarks in video can easily be removed by re-rendering the
video, which shuffles the bits around, making the hidden watermark
disappear again. Obviously, if they are hiddin in a safe area, where one
can put specific user-data, which is "outside" the video-information, this
won't happen. But a geek can find those areas in publications, and simply
write an eraser.

cheers

-martin-
--

[Back to original message]