ลายน้ำ

Visible watermarks overlay text or logos on images to protect intellectual property while displaying work publicly. Effective watermarks are visible enough to deter theft but subtle enough not to ruin the viewing experience — semi-transparent center-positioned marks are harder to crop out than corner marks. Invisible watermarks embed data in the pixel values using steganography, allowing copyright holders to prove ownership without visible marks. The tension between protection and presentation leads many photographers to watermark web-resolution previews while delivering unwatermarked full-resolution files to paying clients. AI watermark removal tools have made visible watermarks less effective as protection, shifting emphasis toward invisible digital watermarks and metadata-based copyright management.