Method for estimating the shape of an object from IR image shading

A circuit for estimating the shape of an object that emits infrared radiation comprising:

• a sensor having an image plane, said image plane comprising a plurality of pixels;
• circuitry coupled to said sensor for measuring the intensity of the emitted infrared radiation received at each of said pixels;
• circuitry for relating the intensity of radiation reaching each of said pixels as a function of the surface gradient of an associated point on the object;
• and
• circuitry for determining the surface gradient of a plurality of points associated with each of said pixels as a function of the difference between the intensity measured at each of said pixel points on said image plane and the intensity of said radiation reaching said pixel point as a function of said surface gradients;
• and
• circuitry for consolidating each of said surface gradients associated with each of said points on said surface and constructing therefrom an estimate of the shape of said surface.

A system for estimating the shape of an object that emits infrared radiation, the system comprising:

• a sensor having an image plane, said image plane comprising a plurality of pixels;
• means, coupled to said sensor, for measuring the intensity of the emitted infrared radiation received at each of said pixels;
• means for relating the intensity of radiation reaching each of said pixels as a function of the surface gradient of an associated point on the object;
• and
• means for determining the surface gradient of a plurality of points associated with each of said pixels as a function of the difference between the intensity measured at each of said pixel points on said image plane and the intensity of said radiation reaching said pixel point as a function of said surface gradients;
• and
• means for consolidating each of said surface gradients associated with each of said points on said surface and constructing therefrom an estimate of the shape of said surface.