1.  Technical Field
The field of the currently claimed embodiments of this invention relates to endoscopic imaging, and more particularly to stereo reconstruction from monoscopic endoscopic images. 
2.  Discussion of Related Art
Endoscopy is extremely common and is often used for diagnostic purposes through natural orifices (e.g. nose, throat, gastrointestinal tract).  FIG.  1 illustrates the use of an intra-nasal laryngeal flexible endoscope.  Most medical flexible endoscopes are monoscopic, and give the user no sense of depth perception.  This presents challenges when the goal is to obtain accurate measurements of anatomical structures, such as the diameter of the airway or sinus passages, which are highly relevant for many clinical procedures.  The current primary method used to measure the airway diameter is to invasively insert various sizes of endotracheal tubes into the throat and measure when the tube stops sealing correctly.  This can be time consuming and can result in trauma to the soft tissues in the throat. 
High quality modern flexible endoscopes such as distal-chip scopes may have a camera chip embedded in the end of the scope, as shown in FIG.  2.  The camera chip 200 may provide superior image quality compared to fiber-optic scopes, and may also free up space in the scope shaft for an open lumen 202, also known as a working channel, through which instruments may be inserted.  Diagnostic endoscopy in the clinic is far more frequent than any surgery, and precise 3-D measurements could significantly simplify and enhance many diagnostic tests such as measuring airway size.  An inexpensive, simple, quick, and disposable solution is needed for performing stereo reconstruction from monoscopic endoscopic images.