How to copyright or otherwise protect images online
There are different methods users can use to help protect and prevent other users copying, hotlinking, or otherwise using your image without your consent. Keep in mind that none of the methods available will protect your images 100% from all users. However, can help protect you from the majority of users online.
URL, copyright, or watermark on images
Adding your company name, photographer name, website URL, or copyright is one of the easiest and quickest methods of helping to protect and identify images you post online.
Below is a visible Computer Hope URL that is below the image. If a user were to copy this image or hotlink the image the URL would be copied with the image. Of course adamant users who wished to use this image as their own could crop the image and claim it as their own. However, could discourage users who want to copy multiple images from your site and if hotlinked is a form of advertising.
Next, is an example of a visible watermark of Computer Hope URL. Watermarks are often more intrusive to the image; however, can be very time consuming to eliminate from an image if placed in a critical portion of the image. For example across the middle of the image. Keep in mind that a watermark can still be cropped out of an image, especially if placed in a corner like the example below. If the watermark is too light as in the example below, it may not be adequately legible.
HTML Table solution
Below are some additional simple solution in helping to protect your images online by using traditional HTML tables. In the first example below, a transparent foreground image is used to protect another image, which is in the background. The transparent 5x6 pixel image is stretched and overlaid in front of the image we want to protect. Both are in a one-row, one-column table, and the protected image is set to be the table's background image. If a user was to right-click the image and save the image it would save the small, transparent dot.gif image instead of the image you want to protect. Below is a working example of this technique.
Below is the source code used to create the above example.
<tr><td background="http://www.computerhope.com/issues/pictures/cexample.gif" width="100"><img src="http://www.computerhope.com/dot.gif" width="231" height="58"></td></tr>
Next, is another example using the same code as before, except this example is using the copyright.gif image, which is a transparent image with the text "(c) Computer Hope - 2007." This technique could be used to not only help protect the image but display a copyright watermark on the image. Keep in mind though that users who know to view the source code and locate the image URL in the code would be able to copy the image without the copyright or watermark.
Prevent indexing with robots.txt
Keep search engines and other bots from creating copies of your images or storing those images on another server or local computer by creating a robots.txt file. Store all your images in one directory such as "images" and then restrict all bots and other crawlers from that directory by creating a robots.txt file with the following two lines.
If your images are scattered throughout your website, or in the same directory as your HTML files which you want search engines to index, you can add the below lines to your robots.txt file. These lines will deny these four specific bots from indexing your site's images.
Additional information about this file can be found on our robots.txt overview page.
Third-party companies software products
You can also utilize third-party companies products to help protect images. Below is a listing of some of these companies in alphabetic order and the services they offer. They are all not free and many of them offer no more protection then the solutions mentioned above. However, many of them can help provide easier installation and setup, additional services such as backing up, tracking, and automatic watermarking.
Artist Scope - Offers software and solutions to help protect images by preventing right-clicking and utilizes techniques such as DHTML and no caching.
CopySafe - One of the most effective products we've seen that helps protect images. The product requires visitors download a small plug-in that is used to display and help protect the image. This plug-in ch000977.htm prohibits users from using the print screen key on their keyboard, a method of copying images that defeats almost every other protection. Unfortunately, this product can also cause frustration by the viewer as it disables other features on the computer while pictures are being viewed. For example, while testing this on a Windows XP computer this product disables the Windows Start and Taskbar until the page utilizing this plug-in was closed.
DigiMarc MyPictureMarc - Provides a solution for digital watermarking and tracking for locating misuse and to see where your images are being shown.
Third-party company web services
There are different online services that help protect your images, as well as print and sell.