Projection-based MR Video

We have been engaged in the researches on the active lighting techniques for twenty years. At first, we proposed a method to measure the 3-D shape of the object by projecting multiple patterns of structured light, because it is much faster than the method with scanning slit of light, and dense range image can be measured. For this purpose, we made a projector which consists of mechanically-changeable masks, but it was soon replaced by a specially-made liquid crystal panel with many slit segments. From the fact, we can proudly declare that the projector is not a diverted device but exclusively developed as a part of projector-camera systems, and the projection target is originally not a planar screen but a real scene with varied depth. Actually, this infant device was successful and commercially enough practical for 3-D shape measurement, but unfortunately we had to wait for the evolution of panel display technology more than a decade, to make a step to the studies which utilizes full duality between cameras and projectors.

In the middle of 1990s, many researchers started using video projectors. Since we are computer vision researchers, we used the flexibility of video projector not for a interaction technique but improving performance of 3-D measurement such as motion tracking. However, we were also aware of its advantage as a visualization tool in a real scene. Alike to the other research activities, we have confirmed that the projector can change the seen color, texture and specular of the real object. In addition, faked shade projected on the object make it possible to change our interpretation of its shape. Furthermore, the traditional shape measurement method we had developed is seamlessly combined with the visualization technique.

In this movie, we summarize the history and progress on light projection methodologies in our laboratory.