We propose a new technology that can be used to invisibly embed information into the images of real objects that are captured with a video camera. This technique uses illumination that invisibly contains certain information. Because the illumination on a real object contains information, an image of the object taken with a video camera also contains information although it cannot be seen in the captured image. This information can be extracted by image processing. It uses temporally luminance modulated patterns as invisible information. The amplitude of the modulation is too small to perceive. The frequency of modulation is the same as the frame frequency of the projector that is used as a lighting device. The frame images over a certain period are added up after the sign of the even- or odd-numbered frames is changed. Changes in brightness by modulation in each frame are accumulated over the frames. However, the object and background image are removed because the even and odd frames are opposite in sign. As a result, the patterns become visible. We conducted experiments and the results from these revealed that invisible patterns could be read out. Moreover, we evaluated the invisibility of the embedded patterns and confirmed that conditions existed where both the invisibility and readability of the patterns were simultaneously satisfied.
This paper presents a technique that can non-destructively read out information embedded inside real objects by using far-infrared-light. We propose a technique that can protect the copyrights of digital content for homemade products using digital fabrication technologies such as those used in 3D printers. It embeds information on copyrights inside real objects produced by 3D printers by forming fine structures inside the objects as a watermark that cannot be observed from the outside. Fine structures are formed near the surface inside real objects when they are being fabricated. Information embedded inside real objects needs to be read out non-destructively. We used a technique that could non-destructively read out information from inside real objects by using far-infrared light. We conducted experiments where we structured fine cavities inside objects. The disposition of the fine domain contained valuable information. We used the flat and curved surfaces of the objects to identify them. The results obtained from the experiments demonstrated that the disposition patterns of the fine structures appeared on the surface of objects as a temperature profile when far-infrared light was irradiated on their surface. Embedded information could be read out successfully by analyzing the temperature profile images of the surface of the objects that were captured with thermography and these results demonstrated the feasibility of the technique we propose.
Conference Committee Involvement (1)
IEEE International Geoscience and Remote Sensing Symposium