You can create an image or text layer to hold your watermark. Once that's ready, set the opacity (a sliding bar found just above the layers) to whatever you'd like. If that doesn't quite create the effect you want, you can try adjusting the Mode (just above the opacity bar). Try combining them until you get what you're after.

Good luck! MFisher

On Sun, Apr 14, 2013 at 11:19 AM, WanderingPen wrote:

I would like to add a hidden watermark to my photos, but not sure how to do so.
I did find a tutorial of how to make the watermark in GIMP, but it was written
using an old version of GIMP. I have the current 2.8 version.

Thanks in advance for your assistance. It's greatly appreciated.

-- WanderingPen (via www.gimpusers.com/forums) _______________________________________________ gimp-user-list mailing list
gimp-user-list@gnome.org
https://mail.gnome.org/mailman/listinfo/gimp-user-list

On 04/14/2013 12:19 PM, WanderingPen wrote:

I would like to add a hidden watermark to my photos, but not sure how to do so. I did find a tutorial of how to make the watermark in GIMP, but it was written using an old version of GIMP. I have the current 2.8 version.

Transparent vs. Hidden is a potential question. We often see "transparent" watermarks on commercial clip art, typically a mosaic of copyright notices positioned to "ruin" the image while allowing the original to show through. This is easily done via a text or image layer with its transparency adjusted.

To create a "really" hidden watermark with the GIMP, see this tutorial, and a plugin using the same method:

http://www.gimpdome.com/gimp-general-use/hidden-watermarks-in-gimp/ http://registry.gimp.org/node/21024

Not sure about the plugin, but the tutorial should work on any recent version of the GIMP. I just tested it in GIMP 2.8 and it worked as advertised.

The plus side: This kind of watermark is very hard to spot, and difficult to remove even if someone realizes that it is present.

The minus side: Digging a hidden watermark back out of a marked image and reading it, requires a copy of both the original and the watermarked image, and involves doing operations to reveal the difference between the marked and unmarked versions. You may need to hire an expert witness if you need to introduce this kind of watermark into evidence in a Court proceeding, to do the watermark extraction and render an "opinion" that it is genuine.

By the time all is said and done, maybe it would be better to e-mail a copy of the original to yourself via a webmail service. A printed copy of this message provides a 3rd party time stamp, for proof of priority of publication. For a large number of images, e-mailing MD5 or SHA checksums of your original files to yourself may be a more practicable method of getting a 3rd party time stamp.

:o)

Steve

. I'm not sure how to save it as a new pattern. Can
you help me with that?

You don't need anything complicated. Do it simple way:

When Your watermark is on separate layer, the easiest way is to copy this layer to a new file and save it. Later You just: 1)open this file with "watermark" only, 2)select all and
3)copy to a new layer in files, You want to protect. It's fast and effective solution. That's partly my way. I don't care about opacity and mode so much - i adjust it every time to get desired effect.

What is important: Your watermark will have some resolution and size. When You'll get Your watermark in new file - crop it to eliminate unnecessary space around.
While copying watermark as a new layer it's easier to position it or resize when there's no unnecessary empty space around.

If You want to have slightly better "theft detterent": Put some gradient, or any kind of changing tones on "watermark" image. It's ugly but when You play with modes, and flatten watermarked photography ... it is rather hard to undo. For each photo You adjust mode and opacity individually (to reduce the ugliness of watermark). Just forget that Gimp can remember mode and opacity of a layer.

Good luck
Dominik

On 04/15/2013 01:29 AM, Steve Kinney wrote:

On 04/14/2013 12:19 PM, WanderingPen wrote:

I would like to add a hidden watermark to my photos, but not sure how to do so. I did find a tutorial of how to make the watermark in GIMP, but it was written using an old version of GIMP. I have the current 2.8 version.

Transparent vs. Hidden is a potential question. We often see "transparent" watermarks on commercial clip art, typically a mosaic of copyright notices positioned to "ruin" the image while allowing the original to show through. This is easily done via a text or image layer with its transparency adjusted.

To create a "really" hidden watermark with the GIMP, see this tutorial, and a plugin using the same method:

http://www.gimpdome.com/gimp-general-use/hidden-watermarks-in-gimp/ http://registry.gimp.org/node/21024

Not sure about the plugin, but the tutorial should work on any recent version of the GIMP. I just tested it in GIMP 2.8 and it worked as advertised.

The plus side: This kind of watermark is very hard to spot, and difficult to remove even if someone realizes that it is present.

The minus side: Digging a hidden watermark back out of a marked image and reading it, requires a copy of both the original and the watermarked image, and involves doing operations to reveal the difference between the marked and unmarked versions. You may need to hire an expert witness if you need to introduce this kind of watermark into evidence in a Court proceeding, to do the watermark extraction and render an "opinion" that it is genuine.

By the time all is said and done, maybe it would be better to e-mail a copy of the original to yourself via a webmail service. A printed copy of this message provides a 3rd party time stamp, for proof of priority of publication. For a large number of images, e-mailing MD5 or SHA checksums of your original files to yourself may be a more practicable method of getting a 3rd party time stamp.

:o)

Steve

For photos, the best way to demonstrate ownership it to publish a slightly cropped version and keep the full version for yourself (and the courts, if necessary)

Ofnuts wrote:

For photos, the best way to demonstrate ownership it to publish a slightly cropped version and keep the full version for yourself (and the courts, if necessary)

I am not a lawyer, but I understand that this may not be the best advice for users domiciled in the USA. US domiciled users may want to consider the what is written on page 7 about registration in copyright circular 1 published by the US copyright office. It states there that for while copyright is automatic in the US, for an action on copyright infringement to be considered in US federal courts, the copyright must be registered.

Now, registration costs money, but I understand that one can assemble all of one's photos for a year, burn them to a set of optical media, and copyright the whole collection, including it's individual contents, for a single fee.

Turning to the original question, what I would do is to create a new layer with the copyright text in it, where the text is a very dark gray, with an RGB value of, say, 080808. I would then change the mode to "subtract" in the layer dialog window, and merge the two layers together. If you want the watermark more visible, use a lighter gray, 0f0f0f, if less visible, use a smaller value: 040404, perhaps.

ns