Dynamic control of multiple focal-plane projections for eliminating defocus and occlusion

This paper presents a novel dynamic control of multiple focal-plane projections. Our approach multiplexes the projectors' focal-planes so that all the displayed images are focused. The projectors are placed at various locations with various directions in the scene so that there is no occlusion of the projection light even for dynamically moving objects. Our approach compensates for defocus blur, oblique blur (loss of high-spatial-frequency components according to the incidence angle of the projection light), and cast shadows of projected images. This is achieved by selecting an optimal projector that can display the finest image for each point of the object surface by comparing the projectors' point spread functions (PSFs). The proposed approach requires geometric calibration to be performed only once in advance. Our approach can compute PSFs without any additional calibrations even when the surface moves if it is tracked by an external sensor. The method is particularly useful in interactive systems in which the object to be projected is tracked.