Underwater Stereo using Refraction-free Image Synthesized from Light Field Camera
This addresses the challenge of accurate underwater 3D reconstruction for applications like marine robotics or inspection, though it is incremental as it builds on existing light field and stereo techniques.
The paper tackles the problem of underwater image distortion due to refraction by proposing a technique to synthesize refraction-free images from light field camera data, and uses these images for stereo 3D reconstruction, showing improved results compared to previous approximation-based methods.
There is a strong demand on capturing underwater scenes without distortions caused by refraction. Since a light field camera can capture several light rays at each point of an image plane from various directions, if geometrically correct rays are chosen, it is possible to synthesize a refraction-free image. In this paper, we propose a novel technique to efficiently select such rays to synthesize a refraction-free image from an underwater image captured by a light field camera. In addition, we propose a stereo technique to reconstruct 3D shapes using a pair of our refraction-free images, which are central projection. In the experiment, we captured several underwater scenes by two light field cameras, synthesized refraction free images and applied stereo technique to reconstruct 3D shapes. The results are compared with previous techniques which are based on approximation, showing the strength of our method.