Sometimes it can be a difficult decision for a photographer -- do I include a watermark on my photographs that is small, out of the way, and doesn't change the image itself? Or should I blast a large watermark across the whole thing, making it impossible for anybody to use the photograph without my permission? Or, in some cases, is it worth watermarking at all?
The Computer Vision Foundation published an interesting paper recently discussing the next stage of technology, and how that difficult decision may not make a difference when it comes to how and where to watermark. In the paper On the Effectiveness of Visible Watermarks, a team of researchers from Google discovered that one of the most common forms of watermarking is not as effective as content creators may believe. Namely, the semi-transparent logo or notice placed over the main part of an image (commonly used by stock agencies and other large distributors of works) can easily be reviewed, analyzed, and removed from any image entirely. This is especially true if that watermark is applied consistently to a large number of works.
Interestingly, even traditional variation in watermarking did not change the results of Google's review, as "randomly changing the position of the watermark across the collection does not prevent such an attack from detecting and removing the watermark, nor do random changes in the watermark’s opacity or color."
The only way to effectively stop this type of large-scale analysis and removal of watermarking was, Google discovered, to use "geometric variations," or small, almost imperceptible random variations to applied watermarks which keep the attacker from being able to correctly identify and process out the watermarking. The result of those added variations are remnants of the original watermark left visible on the source photograph, even after repeated attempts to remove it.
While a quick read of articles about this process may leave a photographer wondering why Google would ever be showing infringers how to more effectively remove watermarks, it is clear that Google's research is directed towards helping photographers and content creators understand what is possible with today's technology, and providing recommendations as to practices that may help content creators avoid the pitfalls of unjustified confidence in their own protective practices. In fact, Google optimistically explains that:
We believe our work can inspire development of advanced watermarking techniques for the digital photography and stock image industries.
Indeed. Let's keep our fingers crossed that the stock agencies, photography software companies, and other entities interested in the protection of rights are paying attention and willing to make these advanced watermarking technologies generally available.
So the decision of how to watermark has a new wrinkle. The safest bet is to follow the requirements of the Copyright Act. Place the symbol ©, the year of the first publication of the work, and the name of the owner of the copyright in a place on the work that gives reasonable notice of the claim of copyright. 17 USC 401(b-c). Whether that covers the image or sits in the bottom right corner is up to you -- and according to Google, may not matter as much as you think it does until more advanced watermarking technology is available.
As for the decision whether to watermark? It's always a great idea, especially if you have any interest in protecting the rights to your work. After all, not only does it make it less likely that your work will be infringed, but if that watermark is removed by an infringer you may be entitled to additional recovery on top of any copyright infringement damages. It's an easy and straightforward way to give you a better ability to defend your rights.