Apparatus and methods for determining the three-dimensional shape of an object using active illumination and relative blurring in two-images due to defocus
AssigneeThe Trustees of Columbia University in the City of New York
InventorsShree Nayar, Minori Noguchi, Masahiro Wantanabe
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Abstract
A method and apparatus for mapping depth of an object (22) in a preferred arrangement uses a projected light pattern to provide a selected texture to the object (22) along the optical axis (24) of observation. An imaging system senses (32, 34) first and second images of the object (22) with the projected light pattern and compares the defocused of the projected pattern in the images to determine relative depth of elemental portions of the object (22).
Claims51
A method for mapping a three-dimensional stricture by depth from defocus, comprising the steps of:
- (a) illuminating said structure with a preselected illumination pattern;
- (b) sensing at least a first image and a second image of said illuminated structure with different imaging parameters;
- and
- (c) determining a relative blur between at least one elemental portion of said first image and at least one elemental portion of said second image which correspond to the same portion of said three-dimensional structure to identify depth of corresponding elemental portions of said three-dimensional structure.
A method for mapping a three-dimensional structure by depth from defocus, comprising the steps of:
- (a) illuminating said structure with a preselected illumination pattern comprising a rectangular grid projected along an optical axis;
- (b) sensing at least a first image and a second image of said illuminated structure from said optical axis using a constant magnification imaging system and at imaging planes with different locations with respect to a focal plane of said imaging system;
- and
- (c) determining a relative blur between at least one elemental portion of said first image and at least one elemental portion of said second image which correspond to the same portion of said three-dimensional structure to identify depth of corresponding elemental portions of said three dimensional structure.
Apparatus for measuring a three-dimensional structure of a scene by depth from defocus, comprising:
- (a) active illumination means for illuminating the scene with a preselected illumination pattern;
- (b) sensor means, optically coupled to said illuminating means, for sensing at least a first image and a second image of the scene with differing optical or imaging parameters;
- (c) depth measurement means, coupled to said sensor means, for measuring a relative blur between at least one elemental portion of said first image and at least one elemental portion of said second image which correspond to the same portion of said three-dimensional structure to identify depth of said three-dimensional structure;
- and
- (d) scene recovery means, coupled to said measurement means, for reconstructing said three-dimensional structure of said sensed scene from said measured relative blur of said sensed images.
Dependencies are inferred from the claim text.