Teemärgistus

Teemärgistus, also known as watermarking, is a technique used to embed a secondary image or pattern into a primary image, video, or digital document. The purpose of watermarking is to protect the intellectual property of the content creator by making it difficult to copy or distribute the content without authorization. Watermarks can be visible or invisible, depending on the application and the level of protection required.

Visible watermarks are typically used in print media, such as banknotes and official documents, to deter counterfeiting. They are usually faint and placed in a way that does not interfere with the primary content. Invisible watermarks, on the other hand, are embedded in a way that does not affect the appearance of the primary content but can be detected using specialized software.

Watermarking techniques can be categorized into spatial domain and frequency domain methods. Spatial domain methods involve directly modifying the pixel values of the primary image, while frequency domain methods involve transforming the image into a different domain, such as the Fourier or wavelet domain, and then embedding the watermark.

Watermarking has a wide range of applications, including copyright protection, authentication, and tamper detection. It is used in various industries, such as publishing, broadcasting, and digital media, to protect valuable content from unauthorized use. However, watermarking is not foolproof, and advanced techniques can be used to remove or alter watermarks. Therefore, it is often used in conjunction with other security measures to provide comprehensive protection.