A 3D scene acquisition and reconstruction system via optical axial scanning

In recent years, three-dimensional (3D) display technology has developed rapidly, and it is widely used in education, medical, military and other fields. 3D holographic display is regarded as the ultimate solution of 3D display. However, the lack of 3D content is one of the challenges that has been faced by 3D holographic display. The traditional method uses light-field camera and RGB-D camera to obtain 3D information of real scene, which has the problems of high-system complexity and long-time consumption. Here, we proposed a 3D scene acquisition and reconstruction system based on optical axial scanning. First an electrically tunable lens (ETL) was used for high-speed focus shift (up to 2.5 ms). A CCD camera was synchronized with the ETL to acquire multi-focused image sequence of real scene. Then, Tenengrad operator was used to obtain the focusing area of each multi-focused image, and the 3D image were obtained. Finally, the Computer-generated Hologram (CGH) can be obtained by the layer-based diffraction algorithm. The CGH was loaded onto the space light modulator to reconstruct the 3D holographic image. The experimental results verify the feasibility of the system. This method will expand the application of 3D holographic display in the field of education, advertising, entertainment, and other fields.