Computer-aided visual model for ensuring video watermarking transparency
Jana Dittmann, Anirban Mukherjee, Martin Steinebach · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2001
Digital watermarking is a technology for copyright protection and protection against unauthorized access and modification of multimedia material. The most important properties of digital watermarking techniques are robustness, security, imperceptibility/ transparency, complexity, capacity and possibility of verification. Robustness means resistance to 'blind', non-targeted modifications, or common media operations. A transparent watermark causes no artifacts or quality loss. A maximum of robustness cannot be achieved at the same time as a maximum of transparency as a higher robustness requires stronger media modifications. Transparency is based on the properties of the human visual system or the human auditory system. It is an often-neglected part of a watermarking evaluation scheme. We introduce a computer aided visual model based on a visual modulation threshold function which is used to test the degree of transparency of the watermark in watermarked multimedia material using linear system theory. We describe our test environment for the model and show how it is implemented in 5 steps representing the essential parts of the visual model: Sampling, band pass contrast response, oriented response, transducer and distance. The model takes two digital images as the input of the and returns a probability that an observer can distinguish the two pictures.