As anyone who’s ever illegally downloaded an MP3 file already knows, stealing a digital asset is really easy. With Web-based digital images it’s even easier. Whether your work is delivered on-line or via physical prints, it’s worth taking a few extra steps to help protect your rights as a creator.
In theory, copyright itself is fairly simple. From the moment you create a work, you own the copyright. Proving that ownership can be a little tricky, as can discovering that your work has been stolen. This article provides details on the working of current copyright law and should help you understand what you own and how to establish that ownership. In this column, we’re going to look at some of the tools that are available to help you mark and track your images, so as to better discover image theft, and to help you prove your copyright. Some of the tools discussed here will work with print or electronic distribution, but most are strictly for online protection. In some cases, you may want to use a combination of multiple techniques.
Watermarking an Image
Placing a visible watermark is a great way of establishing your ownership of an image while simultaneously deterring theft. After all, an image is far less useful if it’s got a big “Copyright” logo burned into it. The downside to this approach, of course, is that your lovely compositions will be marred by a graphic and, depending on where you position the watermark, there’s no reason an image thief can’t just crop it out.
iWatermark, a stand-alone app for Mac and Windows is probably the easiest way to batch process the addition of embossed-looking watermarks. iWatermark allows you to create text or image watermarks, in addition to re-sizing and cropping your images. For quickly cranking out watermarked thumbnails for the Web, iWatermark may be your easiest option.
You can easily create watermarks in Photoshop using a variety of techniques. Here’s a technique that creates an embossed look (see Figure 1):
- Create a new Layer.
- Select black as the foreground color.
- Use the type tool to enter the text of your watermark. If you want the watermark in a left-hand corner, then ensure that left-justified is selected and click appropriately. For a right-side watermark, use right-justified text.
- Choose Filter>Stylize>Emboss to add an embossed look to your text. Default settings are probably fine, but you can always tweak them to increase the strength of the watermark. (The Emboss filter will probably warn you that it needs to rasterize the type layer. Let it do this.)
- Lower the opacity of the watermark layer, to taste.
Figure 1: Using Photoshop’s Emboss filter you can create an unobtrusive watermark that can be batch processed.You can create an Action of this process for easy application and batch processing (just create a new Action in the Actions palette, and hit Record before you follow the steps). However, if you intend to watermark images of different sizes, you may need to create separate actions with different-sized type: 18-point text in a 640 x 480 image is going to look substantially larger than 18-point text in a 1024 x 768 image. Also, for accurate positioning in images of different sizes, you will need to be sure that you set the left- or right-justification properly, as described above. Because the watermark is sitting on its own layer, you can easily remove it or replace it later.
If you don’t like the Embossed look, try this approach (see Figure 2):
- Click and hold on the Text tool in the main tool palette. This will pop out the menu of alternate text tools. Select the Type Mask tool.
- Enter your text as you did in the previous example. When you’re finished, hit the Commit button (the giant check mark) in the toolbar at the top of the screen. Your text will now appear as a selection.
- In the Layers palette, create a new Levels Adjustment Layer. Because you already have a selection defined, the Layers adjustment will be constrained to just that selection. In the Levels dialog box that appears, drag the black Output slider to create a light, translucent watermark. Drag the white Output slider to create a dark watermark.
Figure 2: Using a simple masked Levels effect creates a translucent watermark that’s a little easier to read at small sizes than the embossed watermark.This procedure can also be recorded as an action, and is well suited to batch processing. Like the embossing technique, this watermark is also kept on a discreet layer, making it simple to remove or alter later.
Invisible Watermarking
As mentioned above, though visible watermarks establish clear ownership, they can easily be cropped out. You can repeat your watermark across your image (iWatermark will do this for you), but this seriously mars your work. Invisible digital watermarks are not only resistant to cropping, they don’t clutter up your image, and they can survive resizing, cropping, and even translation into other media. For example, if someone prints an image off of your Web site, there’s a good chance that you can detect the watermark in the printed output.
Photoshop includes a built-in watermarking technology called ImageBridge from the Digimarc Corporation. If you look under the Filters menu, you’ll see a DigiMarc submenu that provides options for adding and reading watermarks.
Digimarc watermarks work by analyzing the noise that naturally occurs in your image. Once the plug-in understands the characteristics of the noise, it can encode copyright information into the noise patterns that are already there. Because these noise patterns repeat throughout your image, if the image is cropped or resized, your encoded watermark will most likely survive. And, since the watermark is part of the image, it’s preserved even after the image is printed and reproduced.
When adding a Digimarc watermark, you can select a strength for the watermark. As you increase watermark strength, you also increase the chances that your image will visibly degrade. However, even a strong watermark introduces less visible degradation than you’re likely to see with, say, JPEG compression (see Figure 3)
Figure 3: Before applying a Digimarc watermark (left) and after (right). Even a reasonably strong Digimarc setting (3, in this case) won’t necessarily visibly degrade your image. After adding a watermark, Adobe recommends using Photoshop’s built-in watermark reader to assess the strength of your embedded watermark.
Another advantage of Digimarc watermarks are the additional services provided on Digimarc’s Web site. Before you can ascribe a personal watermark on an image, you must set up an account with Digimarc and generate a Digimarc serial number. This unique identifier is what will actually be encoded into your document.
Once you’ve established an account with Digimarc, and received your unique identifier, you can subscribe to Digimarc services that will automatically scour the Web looking for images that might belong to you. Digimarc will automatically notify you when they detect your images in places where they possibly don’t belong. If Digimarc finds an image, then your watermark is plainly intact, meaning you have excellent proof of ownership.
Copyright Tags
Most popular image formats these days support metadata (or, meta tags), additional bits of text that are stored within the document, and that can include all sorts of information. If you’ve ever used Photoshop (or many other programs) to view the shooting parameters of an image — shutter speed, aperture, ISO, etc. — then you’ve been viewing metadata information.
There are many different tag standards — IPTC, EXIF to name two — that are supported by most modern image processing and cataloging applications. Included in these tag standards are specifications for storing ownership and copyright information. These tags are not specific to Photoshop format, and are supported by TIFF and JPEG formats as well. Because you can include these tags in JPEG images, you can ensure that all images you post to the Web have your copyright information embedded in them.
Open an image in Photoshop and choose File > File Info. This brings up Photoshop’s tag editing interface. Here, you can easily enter all sorts of information including a title, author and description. Toward the bottom of the first page of tags, you’ll find fields for Copyright Status, Copyright Notice, and a Copyright URL (see Figure 4).
Figuure 4: Photoshop’s File Info dialog lets you edit all of the metadata associated with the current document.The Copyright Notice field provides you with a location for entering your copyright text (e.g. “Copyright © 2004, Michaelangelo”). The Copyright Info URL field allows you to enter a web link to your additional copyright info. The Copyright Status pop-up menu lets you activate the Copyright toggle for the image. Change the pop-up from Unknown to Copyright, and you should see a © symbol appear in the document’s title bar. Anyone who opens the image will see this symbol, providing them with an immediate indication that this is a copyrighted image.
The downside to these fields is that there’s no reason they can’t be changed by anyone who downloads your image. However, if someone changes the fields, then you’ve got immediate proof of a willful copyright violation, which might make any resulting legal actions a little easier.
With the new File Browser in Photoshop CS, applying a copyright notice to a batch of images is easier than ever. To begin, you need to make a copyright notice template. In the File Info dialog, enter the standard copyright and author information that you will regularly use.
Once you’ve entered the appropriate info, click on the fly-out menu in the upper-right corner of the File Info dialog box, and choose Save Metadata Template. Give your template a name (e.g. “2004 Copyright”) and hit Okay. Now close out the File Info dialog and go to Photoshop’s File Browser.
Using the File Browser, navigate to the images to which you want to apply your copyright info. Select the images in the File Browser, but don’t open them.
Notice that the File Browser has its own menu bar. From the File Browser’s Edit menu, choose Replace Metadata. The sub-menu should display the metadata template that you created earlier (see Figure 5). Choose it, and each image you selected in the Browser will be tagged with your metadata, just as if you had entered it directly into the File Info dialog.
Figue 5: Use the File Browser’s Edit menu to automatically apply metadata to your images.When Photoshop is done writing the files, click on a single image and you should see your copyright info in the Metadata pane in the lower-left hand corner of the File Browser dialog. Adding metadata will add a few kilobytes to a file, so if you’ve got extreme file size or bandwidth constraints, you’ll need to compress your image further, or choose to not apply your copyright metadata.
Also, note that if you’re working with Raw files, the File Browser provides you with the option of adding the metadata directly to your raw file (just as it does with other file types) or into a sidecar file, a separate text file that is associated with your image.
The Digimarc plug-in will automatically add a Copyright Web Link to your image, as well as activate the Copyright toggle. You’ll still need to add your other copyright and author tag info.
None of these technologies can prevent a user from downloading and saving your images, of course, but most people want to use images legally. If they see that the image has obviously been copyrighted, they’re more likely to look elsewhere for imagery. What’s more, these techniques help quickly establish your ownership of an image, making it easier to discourage a thief — either a deliberate or inadvertent thief — from using your pictures.
This article was last modified on December 14, 2022
This article was first published on December 21, 2004
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