Single shot 3D imaging by active illumination and point-spread-function engineering

Depth information is crucial for 3D scene reconstruction. Combining the advantages of active illumination, a 3D imaging method using engineered active illumination and double-helix point spread function (DH-PSF) is proposed. It projects a dense pattern of dots onto the object's surface, and a commercial camera captures the dot pattern through a pair of micro lens arrays in a 4f configuration, which includes a DH phase array at the 2f position on the Fourier transform plane. DH-PSF encodes depth information of the object, and by measuring the rotation angles of the two lobes of the dots on the object's surface, the distance between the imaging systems can be obtained. Simultaneously, the two-dimensional image of the object can be reconstructed based on the captured images and the known DH-PSF. The proposed 3D imaging method can reconstruct the 3D structure of the object from a single captured 2D image. It has the advantages of improving distance resolution and reducing system complexity.