Research Of Multi-projecting System For Complicated Surface

Recently, with the developing of reality augment technology, projecting system has been able to provide us with a natural process of display and its effect are become more and more fantastic. Today the projector-based display has evolved from single projectors to multi ones, and the display surface can be covered from a planar surface to a complicated one.Large-scale displays as multi-projecting systems are used in scientific visualization, virtual reality and other visually intensive applications. With the increasing of the number of the projector, we can get almost unlimited visual range, arbitrary display resolution, and immersed user experience. Hence, such techniques become a hot research topic in computer science worldwide at present.The most popular methods of photometric calibration can be generalized into two types: edge blending and LAM (luminance attenuation maps). In this paper, we implement and compare the multi-projecting systems based both on blending and LAM. Both these two methods have their advantages and drawbacks. For the method of edge blending, it works fairly well whenever the display surface is fixed or unfixed, also it achieves a fantastic effect when the luminance parameters among the projectors are approximately same. However, it cannot resolve the negative effects caused by the luminance variance among the projectors. This limitation gives birth of the problem of"un-global luminance uniformity". For the method of LAM, it can well solve the problem in blending. Nevertheless, the problem of"luminance inconsistency in the edge of overlapped region"occurs when the surface is unfixed, such as suspended-type projection screen, hung curtains and so on, which always swing slightly. In short, these two methods are mutual complementary.One step forward, we have broken through the restriction of display surface in traditional projector application and provided a new method which combines the blending with luminance attenuation by slightly reducing the area of luminance attenuation in overlapped region, which efficiently solves the problem of"luminance inconsistency in the edge of overlapped region"in LAM and the problem of"un-global luminance uniformity"in blending. In addition, instead of finding the minimum common luminance value in the photometric calibration, we just find a more suitable common luminance value which can well solve the dim problem in camera-based photometric uniformity of prior approaches. Moreover, the process of photometric calibration on multi-projecting system will be no more complicated than before. The method is robust and accurate, and can be implemented with commercial off-the-shelf components.This paper breaks through the restriction of display surface in traditional projector application and improve the algorithm of geometric registration and photometric calibration which ensure that our multi-projecting system can project seamless image on complicated surface. The distributed architecture has been involved to achieve flexibility and scalability. We also consider the device cost and precision. Moreover, he method is robust and accurate, and can be implemented with commercial off-the-shelf components.