What is Watermarking? How It Works and Types Explained
With the rapid spread of digital content, protecting the copyright of images and videos has become more important than ever. Watermarking is a technology that is gaining attention as a solution. In this article, we explain the basics of watermarking, from how it works to its types and use cases.
What is Watermarking?
Watermarking is a technology that embeds information into digital content such as images, audio, and video in a way that is imperceptible to human senses. Think of it as a digital version of the watermarks found on banknotes. The embedded information can be detected and extracted using specialized tools or algorithms. This enables identification of copyright holders, detection of tampering, and tracking of unauthorized copies.
Visible vs. Invisible Watermarks
Watermarks are broadly classified into two types: visible watermarks and invisible watermarks.
Visible Watermarks
This method overlays logos or text on images. Semi-transparent logos seen on stock photo samples are a typical example. While they visually assert copyright, they have the downside of altering the image's appearance.
Invisible Watermarks
This method embeds information in a way that is invisible to the human eye. It can embed copyright or tracking information with virtually no degradation in image quality. The Adobe TrustMark technology used by truvis falls into this category.
Main Uses of Watermarking
Copyright Protection
Embed copyright holder information in images to prove ownership in cases of unauthorized use.
Tamper Detection
Detect modifications by identifying changes in the watermark data when an image has been altered.
Leak Source Tracking
Embed different watermarks for each distribution channel to identify the source of leaks.
Content Authenticity Verification
With the rise of AI-generated content, watermarking is gaining attention as a means to verify the authenticity of original content.
Using truvis
With truvis, you can embed and detect invisible watermarks in images using Adobe TrustMark technology. It's free to use from your web browser, and you can start protecting your copyrights without any specialized knowledge.
Technical Classification of Watermarks
Watermarking technology can be further classified by embedding method. Spatial domain methods directly manipulate pixel values — relatively simple to implement but with limited robustness. Frequency domain methods use DCT (Discrete Cosine Transform) or DWT (Discrete Wavelet Transform) to embed information in frequency components, offering higher resistance to JPEG compression. The latest deep learning methods use neural networks to learn image features and automatically determine optimal embedding positions and strengths. Adobe TrustMark is classified as a deep learning method.
Visible vs. Invisible Watermark Comparison
| Comparison | Visible Watermark | Invisible Watermark |
|---|---|---|
| Visibility | Visible to the eye | Not visible to the eye |
| Impact on Quality | Alters image appearance | Almost no impact |
| Removal Difficulty | Removable with image editing | Extremely difficult to remove |
| Primary Use | Sample image protection | Copyright proof & tracking |
| User Experience | Obstructs image viewing | No impact on viewing |
Real-World Applications of Watermarks
Watermarks are already in practical use across many fields. In broadcasting, TV stations embed watermarks in real-time to track illegal recording and redistribution. In the music industry, embedding purchaser information in audio files helps identify sources of illegal copies. In healthcare, identification information is embedded in X-ray and MRI images to prevent tampering and mix-ups. The principles of watermarking are also applied to banknotes and official documents, playing an important role in preventing counterfeiting. Recently, with the proliferation of AI-generated content, AI watermarking to identify AI-generated images has also gained attention.