3D shape reconstruction endoscope using shape from focus

In this paper, we propose three-dimensional (3-D) shape reconstruction endoscope using shape from focus/defocus (SFF/SFD). 3-D shape measurement that uses the endoscope image sequence can measure both the shape and the texture at the same time. It has some advantages such as the analysis of lesion location that integrates the analysis of shape and texture. And the shape and the texture from the endoscope can be recorded quantitatively. To obtain 3-D information, shape measurement methods using stereo cameras is often used. But in case of narrow space, 3-D reconstruction using focus information such as SFF/SFD is more appropriate in terms of apparatus size. Therefore, we apply SFF method to endoscope for shape reconstruction, and conducted two basic experiments to confirm the possibility of the system using general camera as a first step. First, to estimate the accuracy of shape measurement of the system, shape measurement of the objects that the shape is already-known was conducted. And the error of the system was calculated about 1 to 5 mm. Next, to confirm the possibility to measure biological inner wall, the measurement of inner wall of the pig stomach was conducted, and the shape was reconstructed.