Dense 3D reconstruction with an uncalibrated stereo system usin

g coded structured light

Ryo Furukawa Faculty of Information Sciences, Hiroshima City University, Japan

Hiroshi Kawasaki Faculty of Information Engineering,

Saitama University, Japan

Procams 2005

Objective

• Using CSL– High accuracy– Dense sampling

• Using normal camera and projector– Low cost

• Self-calibration– Moving devices freely

Self-calibrating stereo vision system based on CSL

Approaches

• Solving epipolar constraints directly with nonlinear optimization (Gauss-Newton method)– Estimated parameters:

• Extrinsic parameters+Focal Length of one of the devices(Camera/Projector)

• Resolving scaling ambiguity– Simultaneous reconstruction– Measuring scaling with laser beam

Epipolar constraints

• Epipolar constraint

)),,,((:),( fNfE iii qpt

ip ),( fi q

),,,(: t

Using as a minimizing function? i

i fE 2),(

Extrinsic parameter

),( fEi

Epipolar constraints• When estimating focal length of devices….

– Minimizing ends up

with BIASED estimation of

because effect of noise to the objective function

varies with

f

f

i

i fE 2),(

Epipolar constraints

ip ),( fi q

• Normalization of errors

),(, fDic ),(, fD

ip

i

i fE2),(

~ Minimize

f

fEfE

pci /

),(:),(

~

),(, fD ic ),(, fD ip

Bias of the estimation of is removed. f

Simultaneous reconstruction• Capture multiple scenes• 3D reconstruction simultaneously

Advantages– Consistent scaling– Improving result

• Redundant input

Results

Live Demo

• We plan to do a live demo.

• Please come and look!