Shape from Shading and Optical Flow Used for 3-Dimensional Reconstruction of Endoscope Image

Abstract

Recent year’s endoscopy is widely used in computer assisted surgeries. Three-Dimensional (3D) reconstruction has been presented due to the lack of depth information from endoscope images. One of the fundamental approaches in the domain of computer vision is Shape From Shading (SFS). This algorithm was proposed to obtain the shape of an object from a single intensity image. Because of the severe conditions are required in shape from shading to reconstruct 3D surface. The photometric calibration is proposed from the view of image processing. The calibration is important for illumination-based visualization techniques such as shape-from-shading. The result showed that the stability of surface reconstruction is improved when the photometric calibration is used before shape from shading. But the surface reconstruction from Shape From Shading (SFS) is the relative variation in the gray gradient field. So, the change from relative variation to absolute variation is necessary when the actual size of surroundings have to be known. Then the optical flow is introduced to solve this change in my paper. The optical tracker is also used in this system to capture the pose of endoscopy.