A technique of time domain sequential data embedding into real object image using spatially modulated illumination

We propose a new technique that uses spatially modulated illumination for embedding time domain sequential data into moving picture data. This is based on the “optical watermarking” technology that can be applied to protect “analog” objects like pictures painted by artists from having photographs taken of them illegally. Another important application of optical watermarking is embedding real time data sequence into real object images unconsciously, which may be moving pictures. We carried out experiments that sequential watermarking image data that had 10 fps (frame per second) were irradiated onto objects with projector, and moving image data with the picture rate of 30 fps were taken with a video camera. The result was that the embedded sequential watermarking information could be detected accurately from the obtained moving image data. In the experiments we embedded 256 bit information into watermarking image area of each frame that had the image size of 128 × 128 pixels, that is, the bit-rate of embedding information was 2.5kbps. The experimental results indicate that faster bit-rate and improved detection accuracy may be achieved when lager size of the area of embedding watermarks and higher resolution image for each frame are used.