Fraunhofer Institute has developed digital image watermark technology and Web search system. System lets companies with popular brands, such as Cartier International or Sony, embed watermarks in their pictures. Watermark technology makes slight changes in the color, contrast or brightness of a picture, invisible to the human eye. The search agent scans the Internet for the watermarked images and lists websites carrying them, allowing owners of the images to confirm their authorized use. The system is designed to track pirated audio files in peer-to-peer file-sharing networks.”]
Source: https://www.csoonline.com/article/2120285/digital-image-watermarks-could-combat-trademark-theft.html