Linux Multimedia Hacks

Leave a Watermark

Use the composite tool from ImageMagick to add custom watermarks to your images.

Copy protection, particularly digital copy protection, is a topic that has been discussed more and more over recent years. In the case of protecting graphical content, often what you want the most is simply to prevent people from taking your images and using them as their own. To protect against redistribution, many online image galleries have taken to adding watermarks—logos or text that identify the owners of the content—to their images (see Figure 1-1). The watermark labels the owner of the content kind of like your mom writing your name on your underwear before you went to camp. If someone decides to take your image and host it on their site, they must cut out your watermark and leave an easily identifiable hole in the image. This hack will describe how to use the ImageMagick tool composite to add your own custom watermark to your image gallery.

Before you watermark your images, you must first create the image you will use as a watermark. How the watermark is designed is mostly a matter of taste, but there are a few conventions you can use to make a good watermark:

• Your watermark should have relatively small dimensions as compared to the image you will watermark. This might seem to go without saying, but if a watermark is too big, not only will it prohibit people from copying your image, it will also prohibiting people from seeing your image. Try your watermark on a couple of representative ...