Online community nowadays facing a big problem i.e., online piracy. And, it is very difficult to prevent digital media from illegal copying and distributing. Almost 70% of online users found nothing wrong while copying online content. 22-25% global internet bandwidth only used for Online piracy. But, the unauthorized reproduction or distribution of this copyrighted work is illegal.
To overcome this serious issue, scientists from the University of Chinese Academy of Sciences have developed a new technique. The technique that they have develop is a new light-based technique. It is fast and needs less complex optical setup.
Actually, the technique creates secure, invisible watermarks that are used to detect and prosecute counterfeiting. According to scientists, this technique is used to optically encrypt data or to hide information within images.
Yishi Shi said, “In our research, we use a complex pattern of light, or diffraction pattern, as a unique watermark. The invisible watermark is embedded into the content we are trying to protect. Imperceptibility is one of the most significant advantages of optical watermarking.”
This new technique relies on single-shot ptychography encoding (SPE) technique. Thus, it uses multiple partially overlapping beams off and creates a diffraction pattern from a complex object. In this method, SPE encodes the optical watermark in a single exposure with no mechanical scanning.
To test the method, scientists conducted an optical experiment. Their aim was to show the efficiency of SPE. So, researchers used SPE to create a complex watermark consisting of a diffraction pattern of multiple tiny spots. In addition, scientists used computer processing for embedding the watermark into the images and to scramble diffraction pattern.
The spot size can then reduce in smaller size less than 10 microns. It helps prevent degradation of the host image.
Although, there are various ways to detect authenticity. For example, by subtracting the host image from the watermarked image and then using a special security key and extraction algorithm. If the presence of the watermark is unknown, the watermark could get extract using existing algorithm-based detection methods.
Shi said, “Most methods for optical watermarking explained with simulations only. Our experiment shows that our method is suitable for practical optical watermarking.”
Now, researchers are trying to apply SPE for dynamic watermarking. They are also planning to use SPE for multi-image watermarking and even 3D watermarking.