Endoscope insertion direction detecting system

An endoscope inserting direction detecting system comprising:

• endoscopic image domain dividing means for dividing an endoscopic image, which is imaged and produced by an endoscope inserted into a body cavity, into a plurality of domains;
• pixel sampling means for comparing the values of pixels constituting each of the domains, into which the endoscopic image domain dividing means divides the endoscopic image, with a threshold, and for sampling the distribution of pixels whose values are equal to or larger than the threshold;
• suitability-for-lumen position defining means for defining domains representing suitability for a lumen position;
• direction-of-lumen estimating means for defining a plurality of circles, which have different radii, over the domains representing suitability for a lumen and being defined by the suitability-for-lumen position defining means and the domains of the endoscopic image, and for estimating the direction of a lumen from the distribution of pixels which are sampled by the pixel sampling means because the values thereof are equal to or larger than the threshold and which are placed between the plurality of circles;
• inserting direction determining means for determining an endoscope inserting direction over the domains, which represent suitability for a lumen position, on the basis of the direction of a lumen estimated by the direction-of-lumen estimating means;
• and
• inserting direction display means on which an inserting direction is displayed together with the endoscopic image on the basis of the endoscope inserting direction determined by the inserting direction determining means.