Patent Document ID: 9336601
Application ID: 14528704
Patent Status: 1

Claim One:
1. A computer vision method comprising: deriving, with a processor, a relationship of spatial and temporal image derivatives of an object to bidirectional reflectance distribution function (BRDF) derivatives under camera motion that provides an image sequence; deriving a quasilinear partial differential equation for solving surfaced depth for orthographic projections using the relationship of spatial and temporal image derivatives to bidirectional reflectance distribution function (BRDF) derivatives; solving the surface depth from the quasilinear partial differential equation; and reconstructing an image of the object from the solving of the surface depth for orthographic projections, wherein the BRDF comprises a negative incoming light direction, ω i , and outgoing direction, ω r , both defined with respect to the surface normal, n, and returns the ratio of reflected radiance exiting along ω r to the irradiance incident on the surface from direction ω i , each direction ω is itself parameterized by azimuth angle φ and zenith angle θ, therefore the BRDF as a whole is 4-dimensional and the BRDF has units sr −1 , with steradian (sr) being a unit of solid angle, therefore the BRDF as a whole is 4-dimensional and the BRDF has units sr −1 , with steradian (sr) being a unit of solid angle, wherein the BRDF comprises f r ⁡ ( ω i , ω r ) = ⅆ L r ⁡ ( ω r ) ⅆ E i ⁡ ( ω i ) = ⅆ L r ⁡ ( ω r ) L i ⁡ ( ω i ) ⁢ cos ⁢ ⁢ θ i ⁢ ⅆ ω i where L is radiance, or power per unit solid-angle-in-the-direction-of-a-ray per unit projected-area-perpendicular-to-the-ray, E is irradiance, or power per unit surface area, Ø i is angle between ω i and surface normal, n and index i indicates incident light, whereas index rr indicates reflected light.