Capturing 2 1/2 D depth and texture of time-varying scenes using structured infrared light

In this paper, we describe an approach to simultaneously capture visual appearance and depth of a time-varying scene. Our approach is based on projecting structured infrared (IR) light. Specifically, we project a combination of (a) a static vertical IR stripe pattern, and (b) a horizontal IR laser line sweeping up and down the scene; at the same time, the scene is captured with an IR-sensitive camera. Since IR light is invisible to the human eye, it does not disturb human subjects or interfere with human activities in the scene; in addition, it does not affect the scene's visual appearance as recorded by a color video camera. Vertical lines in the IR frames are identified using the horizontal line, intra-frame tracking, and inter-frame tracking; depth along these lines is reconstructed via triangulation. Interpolating these sparse depth lines within the foreground silhouette of the recorded video sequence, we obtain a dense depth map for every frame in the video sequence. Experimental results corresponding to a dynamic scene with a human subject in motion are presented to demonstrate the effectiveness of our proposed approach.