Originally posted by fotomann_forever:
... Ken Rockwell (!) doesn't have a very high opinion of it. |
Typical of Ken, spouting off on things he's really not paid much attention to. He has a couple good points...
- It does add grain equally to all areas of the image, and increases file sizes somewhat
- It can be removed, with degradation in quality
Beyond the above, he's not spent enough time to know what he's talking about, and yet he offers opinions.
I've tried embedding and then removing the Digimarc watermarks. Removing them is not at all easy, and I have never removed one successfully and wound up with an image that is even remotely usable. I've tried various noise-reduction strategies, tried adding more noise and then running noise reduction, tried cropping, tried cropping plus the various noise strategies...
suffice to say, the Digimarc watermarks are pretty tenacious, more so than I would have guessed! They do in fact result in visible added grain, even when added at default "durability" which is on the lower side. This, to me, is the biggest detractor of the system.
Ken's assumption that software such as Grain Surgery could be used to remove the watermark is no doubt correct, but only at extreme application levels. Further, his example of 40% file size increase, is, IMO, inflated. I applied a watermark at default durability to an image that was quite noise-free and had large smooth areas. The file size increased from 1.46MB to 1.66MB, or +13.7%; not a big deal. |
