关键词: 瞬态成像, 计算成像, 遮挡重构, 逆向问题

Abstract:

With the development of ultrafast imaging devices, transient imaging can record the movement of light on the femtosecond scale. One of its applications is the reconstruction of hidden 3D shapes, which is to reconstruct the three-dimensional structure of objects hidden outside the camera field. Due to the complex structure, the high price and difficult performance-evaluation of the transient imaging hardware system, this paper presents a new reverse reconstruction algorithm and establishes a transient imaging process using software simulation. Beginning with a simplified heatmap function according to the scene, this reverse algorithm introduces the detecting probability to obtain the sampled data of the object in the scene; after that, it computes the global detecting probability of the object using ray-tracing methods and gets a 3D point cloud by thresholding results; finally, the point cloud is visualized in the 3D space. The result shows that the simulation method presented in this paper is able to describe the transient imaging process of a hidden object in a 3D scene, and that the reverse reconstruction algorithm can improve the reconstruction of hidden objects.

Key words: transient imaging, computational photography, looking around the corner, inverse problems