Digital watermarking techniques

By , last updated December 26, 2015

watermark example sftextures purple stock photo securedWith the unbelievable development of the Internet nowadays, most artists in general and photographers in particular have an online presence, showing their art to millions of people, both as a portfolio but also as products to be sold. But with this growing number of online images, image theft has also become a real problem that more and more people have to deal with. The easiest solution that everyone can make use of is to watermark images before making them available online, preventing most problems related to attribution and copyright. Those who are beginners or have never thought about watermarking their images should know that the process is pretty simple and straightforward. Practically anyone with a computer and some basic knowledge of editing and Internet could easily do it in a matter of seconds or minutes.

Editing software

The easiest option to watermark images is to use the same editing software one uses to edit those images, if this is the case. Although not everyone is familiar with the most popular editing software programs, there are simple tutorials to apply a watermark to an image in Adobe Photoshop, GIMP, Corel Paintshop and other similar programs. Most of these even allow automating the process and applying a watermark simply by pressing a button and then adjusting the properties a little. If this seems too hard, once an image needs a watermark, the user can apply the watermark as a PNG image over the original one and then adjust the size, location and opacity.

Here are some of the FREE editing software programs that you can use:

  • GIMP – simple image manipulation program for everybody.
  • Picasa – photo organizing software with some level of editing.
  • Fotor – advanced editing software for many platforms. Allows also batch editing of pictures.
  • Photoscape – easy photo editing software for all users.

Dedicated software

There are dedicated software and applications that do just this thing, applying watermarks to images or even large batches of images. Although these are not free, it is by far the easiest way to watermark large number of images at once.

Watermarking online

This major option is usually free and it implies using a website that provides this service, uploading the image or images and then downloading the watermarked versions. This of course takes some time, but for people who only use it rarely; it does have the advantages of being free and pretty simple. Depending on whether the user wishes to upload the image to a specific site or service online, these might even offer the option of automatically watermarking the images. One could potentially just choose or upload a watermark and never have to worry about this again. There are many ways to watermark an image so it just depends on the purpose and the knowledge of the user which option to choose.

Dynamic CSS

You can visually watermark images by applying some CSS code above the image. This won’t actually protect the image, but it will give visitors a reminder that the artwork is protected. You can either position some text over the image or use a transparent PNG image as a watermark. Here is an example CSS code for such watermarking:

.image_wrapper .watermark {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
opacity: 0.5;
filter:alpha(opacity=50);
}

Dynamic image swap

This is the most difficult technical solution that dynamically swaps full resolution images with the watermarked ones when a visitor views the image. Here is a guy who managed to implement it and wrote a detailed step by step guide. Not everybody managed to repeat the process on their websites though.