Scope modifications to enhance scene depth inference

An imaging system for determining a size of a viewed object, comprising:

• a monocular endoscope;
• an imaging device mounted on the endoscope;
• at least one light source disposed in a fixed position relative to the imaging device;
• a tool positionable relative to the imaging device and the at least one light source;
• and
• a processor configured to receive an image captured by the imaging system and to perform an analysis on the image to determine the size of the viewed object captured using an imaging device mounted on the endoscope and using at least one light source disposed in a fixed position relative to the imaging device determine a size of an object in an image, wherein the processor is configured to:
• identify a tool in the image, wherein the tool is positioned at a first distance from a light source of the monocular endoscope;
• search from a tool edge in the image to detect a shadow edge of a shadow cast from the tool onto a tissue surface included in the image;
• determine corresponding points on the tool and the shadow to measure the shadow to measure a width of the shadow;
• assign a depth to a point on the shadow edge based on the width of the shadow as a second distance;
• calculate a ratio of the first distance to the second distance;
• determine a third distance from the light source to object in the image and a fourth distance from the light source to a surface on which a shadow of the object is visible in the image;
• and
• use the ratio of the first distance to the second distance to determine the size of the viewed object based on the third distance and the fourth distance.

An apparatus comprising:

• a processor configured to perform an analysis on an image captured using an imaging device mounted on an endoscope and using at least one light source disposed in a fixed position relative to the imaging device to determine a size of an object in an image, wherein the processor is configured to:
• identify a tool in the image, wherein the tool is positioned at a first distance from a light source of the monocular endoscope;
• search from a tool edge in the image to detect a shadow edge of a shadow cast from the tool onto a tissue surface included in the image;
• determine corresponding points on the tool and the shadow to measure the shadow to measure a width of the shadow;
• assign a depth to a point on the shadow edge based on the width of the shadow as a second distance;
• calculate a ratio of the first distance to the second distance;
• determine a third distance from the light source to object in the image and a fourth distance from the light source to a surface on which a shadow of the object is visible in the image;
• and
• use the ratio of the first distance to the second distance to determine the size of the object based on the third distance and the fourth distance.