US 9,813,690 B2
Shape and dichromatic BRDF estimation using camera motion
Manmohan Chandaker, Santa Clara, CA (US)
Assigned to NEC Corporation, Tokyo (JP)
Filed by NEC Laboratories America, Inc., Princeton, NJ (US)
Filed on Oct. 10, 2014, as Appl. No. 14/511,649.
Claims priority of provisional application 61/948,728, filed on Mar. 6, 2014.
Claims priority of provisional application 61/948,729, filed on Mar. 6, 2014.
Prior Publication US 2015/0256810 A1, Sep. 10, 2015
Int. Cl. H04N 13/02 (2006.01); G01B 11/24 (2006.01); G06T 15/50 (2011.01); G06T 7/579 (2017.01)
CPC H04N 13/0203 (2013.01) [G01B 11/24 (2013.01); G06T 7/579 (2017.01); G06T 15/506 (2013.01); G06T 2207/20228 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method for shape and material recovery for an object observed by a moving camera, comprising:
detecting a change in image intensity induced by camera motion to corresponding variation in surface geometry and dichromatic reflectance;
receiving a sequence of three or more camera motions to yield a linear system that decouples shape and bidirectional reflectance distribution functions (BRDF) terms;
applying linearities in differential stereo relations to recover shape from camera motion cues, with unknown lighting and unknown dichromatic BRDFs; and
recovering unknown shape and reflectance of the object with dichromatic BRDF, using camera motion cues;
wherein the BRDF is unknown and composed of a sum of dichromatic lobes, comprising using three or more differential motions of the camera to derive a linear system in an albedo and BRDF-derivatives.