We propose a new system to visualize depth-dependent patterns and images on solid objects with complex geometry using multiple projectors. The system, despite consisting of conventional passive LCD projectors, is able to project different images and patterns depending on the spatial location of the object. The technique is based on the simple principle that multiple patterns projected from multiple projectors interfere constructively with each other when their patterns are projected on the same object. Previous techniques based on the same principle can only achieve 1) low resolution volume colorization or 2) high resolution images but only on a limited number of flat planes. In this paper, we discretize a 3D object into a number of 3D points so that high resolution images can be projected onto the complex shapes. We also propose a dynamic ranges expansion technique as well as an efficient optimization procedure based on epipolar constraints. Such technique can be used to the extend projection mapping to have spatial dependency, which is desirable for practical applications. We also demonstrate the system potential as a visual instructor for object placement and assembling. Experiments prove the effectiveness of our method.
@cite_12: Video projectors are rapidly shrinking in size, power consumption, and cost. Such projectors provide unprecedented flexibility to stack, arrange, and aim pixels without the need for moving parts. We present a dense projector display that is optimized in size and resolution to display an autostereoscopic life-sized 3D human face with a wide 110 degree field of view. Applications include 3D teleconferencing and fully synthetic characters for education and interactive entertainment.
@cite_8: We present a concept for a full-parallax light field display achieved by having users look directly into an array of video projectors. Each projector acts as one angularly-varying pixel, so the display's spatial resolution depends on the number of video projectors and the angular resolution depends on the pixel resolution of any one video projector. We prototype a horizontal-parallax-only arrangement by mechanically moving a single pico-projector to an array of positions, and use long-exposure photography to simulate video of a horizontal array. With this setup, we determine the minimal projector density required to produce a continuous image, and describe practical ways to achieve such density and to realize the resulting system. We finally show that if today's pico-projectors become sufficiently inexpensive, immersive full-parallax displays with arbitrarily high spatial and angular resolution will become possible.
Multiple projectors are also used for applications in light-field displays @cite_8 @cite_12 . For these applications, in order to create the large number of rays needed for the light field, each ray is projected separately for a specific viewpoint and is not intended to be mixed with other rays. This is in contrast with our proposed method, where the multiple independent images are created at the intended depths and on the intended surfaces exactly by leveraging the mixing properties of rays from the projectors.