Watermarking textures?

How many people do it, and has it proven useful?

I haven't been doing this, so far. But soon every single texture displayed at TRU will be watermarked. The vendors will all display only a low-rez watermarked sample. You won't get to see the real texture till you buy it.

The barrier for me has been that I hadn't ever found a method of watermarking a texture invisibly that I could believe would prove the least bit useful later. And any visible watermark would render most of my textures worthless, if on the actual texture itself.

I have not released my skin yet, but I do not plan on watermarking it. Frankly, I just don't see how I would ever find the duplicated copies anyway. If I pass someone on the the street and see my skin, I'm not going to assume they have ripped it off, I'm going to assume it was purchased from me.

The next most likely place is slexchange. But usually the images there are so poor that it might be hard to see that it was my skin... especially if the person in question had bothered to change even a few things.

Honestly, it just seems like more trouble than it's worth.

If I was going to bother at all, it would be using a professional system such as digimarc that would hold up in court. But then I have to ask myself, would the average SL user actually be able to pay enough damages to recoup court costs for the litigation.

for vendor situations, you can always do a cheap watermark, instead of using separate uploaded textures, a single "watermark prim" with sample, or you logo or whatever done in alpha, situated in front of the vendor preview... prevents simple abuse like snaphots and print screen, but nothing past that....

on my personal website I display personal art that is cropped, so if I find my art in the wild I have one more layer of verification that mine is the original... that and certain "tells".... wouldn't call any of that watermarking... so I answered Pie... I like pie

Personally, I find watermarking something I can't do without. Demos are extremely important to my customers (try before they buy), and without using watermarks I wouldn't be able to offer demos or securely showcase my work in the manner it is meant to be seen in.

The more stealthy use of watermarking is also quite helpful in tracing the history of a texture that has been in circulation. Invisible weak watermarking can reveal spots that have been manipulated because the watermark gets destroyed as it is manipulated. The invisible strong watermarking is good for proof of origin because it survives manipulation.

It's extremely easy to build watermarks into the layeriing of master files. It's a lot more challenging to remove them once the texture has been flatened. More people should do it.

Ceera, I'd be happy to help you with designing a strong invisible watermark method for your textures. I'm not going to discuss it here, but PM is ok.

you do make a good case though Namssor, I currently have no sample displays that are texture oriented.... so there is no need for me... but I may here shortly (to protect subleted work).... I'm curious, does your invisble watermarking method survive translation into SL?

Thank you, Namssor. With over 1000 of my own textures for sale at TRU, it would be useful if I could protect them better. I'll be in touch with you soon.

Though I shudder at the thought of locating my archived master files for all of those textures, watermarking them all, and re-uploading them all... More likely I'll just start applying it to my newer textures.

JPEG (J2C) conversion into SL is not a problem. I can upload a TGA file into SL with a strong invisible watermark in it, save it back out to my hard drive, even run it through several transforms that would render the actual texture worthless and still extract the watermark with good readability. The watermark can be destroyed, but not without destroying the texture. The only easy way to extract the watermark is with a copy of the master file, which acts like a primer. The primer gives me the neccesary information to reconstruct the watermark.

About a year ago I started a series of threads here as a proof of concept. I gave people a scrambled image with a primer and challenged them to find a solution to revealing the hidden image(s). Without the primer, most of the challenges were essentially unsolvable. Seifert Surface, one of SL's resident mathematicians, confirmed that. A few other people joined in on the fun of posting and solving them. The threads still exist, but the images have long ago been purged :

/109/f4/83553/1.html
/109/d1/83626/1.html
/109/8d/83697/1.html
/109/8d/83697/1.html

The purpose of these challenges was to investigate methods to invisibly embed data in an image as a hackproof weak watermark. There is no real practical application for using them inside SL because they get destroyed during JPEG conversion, but strong watermarking does have practical application inside SL for just about any texture.

I really cool example of visible strong watermarking is what some people have been doing with sculpt maps. Since sculpted prims only use the color information within the map texture, a 32 bit texture can carry a strong visible watermark on the alpha channel without affecting the shape of the sculpty. These sculpt maps are no larger than the preview image in most cases and are vulnerable to screen captures. Introducing transparent areas as watermarking is a great way to copy protect the sculpt maps from screen capture without destroying thier usability.

I have tested certain things cause sometimes I am texture tweaker for my personal use,etc.
And I noticed the Lindens have way to make images show huge 'L" in it regardless of what you do to the image that sometimes shows up even in images from photos that I have experimented with for art purposes.
I am not sure how they do this but I also noticed there are also textures that I have where the lindens names are in owner and creator in inventory.
The Lindens could make things unshareable, because they have with their own textures.
Most I can do with my unique art textures is add something that is unnoticeable that only I would see.
None of my artwork or textures at this point is for sell.

A bot or altered viewer could probably do it automatically...

A large loyal customer base is just as good, if not better than any Bot. It really doesn't matter whether someone obtained the texture legally or not, watermarking allows you to prove where it originated from. If you see someone selling/distributing and claiming authorship of a texture that you know is your creation, watermarking helps you prove that it is your original work.

strong watermarks have always been easy, just an extra layer in the master. I thought you'd devised something to get past the j2k conversion for the weak/invisible WM... which is what prompted my question, thanks for clearing that up =)

Yep. Was just saying that it _could_ be done, not that it necessarily should be done or would be worth the effort.

Weak/Invisible = No
Strong/Invisible = Yes

ok now you've confused me thouroughly...

strong+invisible?

as in "doesn't noticeably alter the apparent viewed image" and "survives conversion to j2k (and theoretically back)" ?

you've got my full attention

It can be done. Here's an example that was compressed into JPEG. Find the watermark.

Stupid question, but wouldn't the date/timestamp on the actual uploaded textures (which I'm assuming exists on every uploaded texture) serve as a sort of poor man's copyright?

That's assuming that the stolen texture is still recognizable as deriving from yours. If its been altered so much that the similarities are not readily visible, I'm not sure how you would even find the stolen textures, much less prove that they are stolen.

EDIT: Kicks self in head for turning off images that don't come from the originating website and turns them back on::

OK, I'm guessing some high contrast spot marking?.... is it possible to give an example of a less random repetitive image? like say a portrait or some such?

My experience has been that I usually find out through customers or competitors about others selling my work. You're not going to know unless it's being sold or given out for free. In most cases I simply had to pull the texture up in the preview window or open it to see the visible watermarks. It blows my mind how many people will simply ignore a big fat © in the middle of a texture. For textures that can't have visible watermarks, put your copyright notice in the description and make it NO MOD if you can. All other full permissions textures can benefit from strong invisible watermarking. Time stamps help a little, but showing people a logo and copyright notice that is clearly undeniable and embedded in the texture in question is as good as a fingerprint. As far as recognizing work that I have created - That's like looking at a signature in and of it's self to me - I know my work at a pixel by pixel level, so a few folds, freckles, blemishes, asymmetries stand out like a sore thumb.

Significantly altering textures (especially clothing and skins) to look different from the original (assumed stolen) texture is a lot of work. Most of the lowlifes that regularly do this are too lazy or incapable of putting in that kind of work themselves. That's why they resort to ripping other peoples work and simply uploading as is, boxing it, and selling it, logos, copyright notices, and all. They don't care. So, watermark your textures folks.

I'll work on another example with less repetition and post it later - just thought this was applicable to those who sell textures for building.

This image is a little harder to hide a watermark in, much less repetative, and has gone through 2 lossy transforms (uploaded into SL as J2C, saved back to HD as TGA, and compressed into JPEG at 70% quality for web posting) after embedding the watermark in it. The watermark is still readable. Can anyone find it?

I'm guessing (and that alone has me sold) the little C dot in the ear? and wouldn't have even gotten that far if I hadn't been looking for it

I'm sold =)

The watermark in this image is nearly as big as the woman's face. Part of a strong watermark's effectiveness is it's ability to remain fully or partially intact through image cropping. This would rule out a small single mark because it could be easily erased through cropping. Whatever that mark on the ear is (ballooned vein) was in the original photo.

If you've ever wondered why JPEG is such a successful compression method for photographic images it is because the human eye has great difficulty differentiating subtle changes in color value. JPEG takes a smooth transition of 16.7 million colors and compresses that data into larger chunks of identical color values while retaining most of the grey level values (which the human eye is much better at differentiating). The human eye has far fewer color receptors on the retina than it does for black and white (light and dark values), so all those chunky rectangular bits of color in a JPEG appear smooth to the human eye. An invisible watermark also takes advantage of the limitations of the human eye/brain in this and several other ways. A computer is free of those limitations and can reveal watermarks of this nature with a primer.

If i had to hazard a guess I'd say it was a yellow mark on that image.... faint beginnings of the bottom part of an S starting by the woman´s lips, bending down, across and upwards on her jawline. If I'm right, it's very very cleverly done.

You're on the right track. 95% of the colors in this image can be distilled down to red and yellow. The JPEG description in my previous post was a hint.

in-game textures I NEVER watermark. It makes it look worse in my opinion. Now, images of my clothing/items and such that I'm using for advertising, I might watermark, especially if being used outside of SL.