Depth enhancement using a scanning fiber optical endoscope

The Single Fiber Scanning Endoscope (SFSE) is a miniature flexible endoscope with unique features that promises to open new minimally invasive procedures for previously inaccessible diseases. There is a need for enhancement of depth cues and 3D measurement in procedures using monoscopic endoscopes. The SFSE uses scanning acquisition that gives it unique imaging properties which are advantageous for 3D vision algorithms -- simultaneous images can be created from multiple sensors all having common viewpoints but different lighting directions. A radiometric dual exists between array and scanning acquisition systems, so scanning acquisition images appear to have the light source originating from the sensors and the viewpoint at the scanner location. Disparity and photometric stereo techniques are investigated. A novel method for interactive virtual lighting allows the surface to be illuminated from any virtual lighting direction, even those not physically possible with endoscope, for use with either monocular or binocular images. This enhances or provides depth cues from shading and parallax. Using the photometric stereo method a 3D mesh representing the surface shape is obtained. A combination of disparity stereo and photometric stereo techniques creates dense range maps and measurements. The ability to make dense 3D measurements allow accurate volume measurements for dosage, risk estimation, and healing progress evaluations.