New technique for capturing images containing invisible depth information on objects using brightness modulated light
Sae Isaka, Kazutake Uehira · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2012
We present a new technique for capturing images where depth information on an object is invisibly and simultaneously embedded in its 2-D image when its image is taken with a camera. An object is illuminated by light that contains invisible information whose characteristics change depending on depth; therefore, the images of objects captured with a camera also invisibly contain such information. This invisible information on depth can be extracted by appropriate image processing from the captured image of the object. Images taken with this technique can be treated as conventional 2-D images because the image format is for conventional 2-D images. 3-D images can also be constructed by abstracting depth information embedded in the image. We carried out experiments including a subjective test and confirmed that the projected pattern could be embedded in the captured image invisibly and its frequency component, from which the depth information on the object can be obtained, could be read out from the captured image. Moreover, we demonstrate that the depth map on a captured image of a practical scene can be obtained using this frequency component although it can now only be applied to scenes with simple configurations such as foregrounds and backgrounds.