I used to use Digimarc myself, but found that it made no difference to images being taken. I have found it just as easy using Tineye to find stolen images, and that's free. Unfortunately, it is not easy to actually take action when images are used internationally, beyond contacting ISP's and requesting they remove the offending content. That's why I stick with visible watermarks now - better to deter, I reckon.
Thanks guys, that's been very informative! I wasn't aware Digimarc had services beyond just watermarking. I'm going to give Tineye a test drive seeing as it's free.
@jinximages Do you find Tineye works? I've done many searches on my images, ones that I know are online because I've given them to bands, but Tineye never pics them up.
@blightygal It takes a while, just like Digimarc's trawling, but I have had success with it a number of times. It can take a couple of months, depending on the location of the images.
@jinximages Thats what I thought too - but I tried pics ranging from 1-5 years old, and I tried a few months ago, and just now for the same ones. Nevermind!
@kimmistephens Digimarc embeds data into the image that can withstand editing, exif stripping, etc, and then they search using that. It's honestly a great idea, because EXIF data (where I usually have my digital copyright stuff) easily gets stripped out by most editing programs, and also sites like Facebook.
read this article :
http://naturephotographyblog.squarespace.com/journal/2010/11/22/watermarks-visible-invisible.html