Light field Laparoscope imaging model and calibration method based on flexible aperture-angular plane

With rapid developments in light field imaging, a great deal of attention has been given to its applications in industrial, medical and other fields due to its ability to perform three-dimensional reconstruction in single-shot. In these applications, Light field Laparoscope (LFL) is an important one, but it often suffers severe micro-lens image deformations that lead to incorrect LFL decoding, calibration and three-dimensional reconstruction. Based on the micro-lens image non-deformation constraint presented by us before, we propose the flexible aperture-angular plane to analyze the LFL imaging model, the modified microlens image non-deformation constraint for 3D LFL system and an advanced two-step calibration method to compute 3D LFL imaging parameters. Moreover, a 3D LFL imaging prototype is designed and calibrated. Experimental results show that microlens image deformations are avoided in this 3D LFL prototype, and the typical RMS re-projection error is about 0.06 pixels.