Jingu Heo

Photometric stereo-based single time-of-flight camera.

We present a method to enhance depth quality of a time-of-flight (ToF) camera without additional devices or hardware modifications. By controlling the turn-off patterns of the LEDs of the camera, we obtain depth and normal maps simultaneously. Sixteen subphase images are acquired with variations in gate-pulse timing and light emission pattern of the camera. The subphase images allow us to obtain a normal map, which are combined with depth maps for improved depth details. These details typically cannot be captured by conventional ToF cameras. By the proposed method, the average of absolute differences between the measured and laser-scanned depth maps has decreased from 4.57 to 3.77 mm.

Eye Tracking based Glasses-free 3D Display by Dynamic Light Field Rendering

Glasses-free 3D display is developed using dynamic light field rendering algorithm in which light field information is mapped in real time based on 3D eye position. We implemented 31.5″ and 10.1″ prototypes.

Feasibility of Eye-tracking based Glasses-free 3D Autostereoscopic Display Systems for Medical 3D Images

Medical image diagnosis processes with stereoscopic depth by 3D display have not been developed widely yet and remain understudied Many stereoscopic displays require glasses that are inappropriate for use in clinical diagnosis/explanation/operating processes in hospitals. An eye-tracking based glasses-free three-dimensional autostereoscopic display monitor system has been developed, and its feasibility for medical 3D images was investigated, as a cardiac CT 3D navigator. Our autostereoscopic system uses slit-barrier with BLU, and it is combined with our vision-based eye tracking system to display 3D images. Dynamic light field rendering technique is applied with the 3D coordinates calculated by the eye-tracker, in order to provide a single viewer the best 3D images with less x-talk. To investigate the feasibility of our autostereoscopic system, 3D volume was rendered from 3D coronary CTA images (512 by 512 by 400). One expert reader identified the three main artery structures (LAD, LCX and RCA) in shorter time than existing 2D display. The reader did not report any eye fatigue or discomfort. In conclusion, we proposed a 3D cardiac CT navigator system with a new glasses-free 3D autostereoscopy, which may improve diagnosis accuracy and fasten diagnosis process.