Is it possible for my image watermark to be read, modified or removed?
Is there a tool that will show if an image contains a watermark and reads, modifies or removes the watermark if used by someone other than the creator of the watermark?
Edit to try and reflect Kerzin's intent, as pointed out in the comments: It's not for knowing how to do it, but whether others can do it to remove watermarks from the generated image, and how difficult it can be.
It depends on the type of watermark you are creating. I am assuming that you are talking about an opaque or semi-transparent logo or text that is usually placed in the corner of an image.
There is a balancing act here. If the watermark is small enough, users can always crop it. But if you make it too big, you make the image unusable. Sometimes this is the intent (for example, take a look at iStockPhoto.com: they use large watermarks above the center of the image, so you can't use the image without buying it). Other times, you don't want to do this (say you're submitting a wallpaper to DeviantArt: you still want people to use an image, but no one is going to use it if the watermark takes up a third of the screen).
If the watermark covers a part of an image that isn't too detailed, users who know what they're doing can use a clone brush or other Photoshop tools from the image. (Similarly, I somehow removed the ugly power lines from a beautiful sunset photo.)
In addition, if the watermark is in the same place on all images and is transparent enough, sophisticated users can create a pixel-based filter from multiple of your images. Under the right circumstances, such a filter can work like magic. (But usually it won't.)
source to share
Generally:
- To detect a watermark that is not visible to the naked eye, you need to have an understanding of the coding scheme.
- it is possible to create a watermark scheme that gives a watermark that cannot be read or definitively confirmed without knowing the secret, however, generally speaking, this is not the purpose of the watermark.
- a watermark that does not distort the image sufficient to be obvious to the naked eye should be removed altogether by manipulations that similarly do not degrade the signal sufficiently to be obvious to the naked eye; however, coming up with the necessary manipulations can be difficult and will certainly require specialized knowledge of the watermarking scheme.
source to share
In most cases, you will not be able to remove the watermark. Not even manually.
If it is not a real simple and / or damaged watermark and the image itself is easy to reconstruct.
There are several tools out there that claim to be able to remove watermarks, but I don't know of any that really depend on the task.
source to share