public class PixelDepthLinearMetric extends Object
Computes the depth (value of z-axis in frame A) for a single point feature given N observations and N-1 rigid camera transforms. The estimate will be optimal an algebraic sense, but not in a Euclidean sense. Two variants are provided in this class, for 2 views and N>1 views. All pixel coordinates are in calibrated units.
This linear estimation of pixel depth is done using the following equation:
λ1*hat(x2)*R*x1 + hat(x2)*T = 0
where λ1 is the pixel depth in the first image, x is an observation in calibrated homogeneous coordinates, and (R,T) is a rigid body transformation. Modified implementation of the algorithm described in .
To go from pixel depth to a 3D coordinate simply multiply the observation in calibrated (z=1) homogeneous coordinates by the returned depth.
 Page 267 in Y. Ma, S. Soatto, J. Kosecka, and S. S. Sastry, "An Invitation to 3-D Vision" Springer-Verlad, 2004
Constructors Constructor Description
depthNViewComputes the pixel depth from N views of the same object. Pixel depth in the first frame.
obs- List of observations on a single feature in normalized coordinates
motion- List of camera motions. Each index 'i' is the motion from view 0 to view i+1.
- depth of the pixels
depth2ViewComputes pixel depth in image 'a' from two observations.
a- Observation in first frame. In calibrated coordinates. Not modified.
b- Observation in second frame. In calibrated coordinates. Not modified.
fromAtoB- Transform from frame a to frame b.
- Pixel depth in first frame. In same units as T inside of fromAtoB.