Unseen Visible Watermarking

A novel data-hiding methodology, denoted as unseen visible watermarking (UVW), is proposed. The proposed scheme is inspired by real-world watermarks and possesses advantages of both visible and invisible watermarking schemes. After watermark embedding, the differences between the original work and the stego work are imperceptible under normal viewing conditions. However, when the hidden message is to be extracted, no explicit watermark extracting module is required. Semantically-meaningful watermark patterns can be directly recognized from the stego work as long as common imaging-related functions, e.g. gamma-correction or even simply changing the user-viewing angle relative to the LCD monitor, are performed. The proposed scheme outperforms existing invisible watermarking methods in its capability to practically convey metadata to users of legacy display devices lacking renewal capability. On the other hand, it does not suffer from the annoying quality-degradation problem of visible watermarking schemes. Limitations and possible extensions of the proposed schemes are also addressed. We believe that many interesting new applications can be facilitated using such unseen visible watermarking schemes.