Structure from Motion Based Approaches to 3D Reconstruction in Minimal Invasive Laparoscopy

摘要

The present article proposes a. Structure from Motion (SfM) methodology to recover the liver surface from endoscopic video sequences. Features from an imaged liver are extracted and tracked for the complete sequence to generate a correspondences lookup table (C-LUT) between all frames. A keyframe selection code extracts two frames, from which the relative pose of the camera is reconstructed using a MS AC-based 5-Point algorithm. Techniques such as an optimal triangulation method and a PnP resection algorithm are also used to obtain an initial 3D surface of the liver. A global Bundle Adjustment step refines the initial reconstruction. Proper parametrization and conditioning of these techniques are compared and evaluated under typical laparoscopic uncertainties arising from patient, illumination, reflections, image quality and organs' location among others. A robotic system and grid patterns are used to provide camera pose and surface ground truth data respectively.