Photorealistic Outcrop at Dallas Post Office

• Accuracy of a few centimeters• Photo registration about 0.7 – 2.7

pixels.• Bring outcrop back to office

photorealistically in three-dimensions• Directly taking measurement on photos

in three-dimensions• Virtual field trip

Objectives

• Rendering the geological outcrop photorealistically in three-dimensions

• Capturing the entire outcrop in three-dimensions and taking back to office

• Additional 3D mapping and measurements back in office.

Traditional Image Registration

• Apply the low order polynomial function to map the image coordinates into world space.

• Only appropriate with a perpendicular perspective and relatively small relief

• Poor accuracy

The georeferenced digital geological map

The DEM

Geological map draped onto terrain surface

Traditional Image Registration

Geometric Measurement

• Rely on stereo image sequences.

• Require a large amount of correspondence points.

• Time consuming.

• Not good for natural surfaces.

Stereo Image Sequence Capture System

Image Registration

• Rely on pinhole model.

• Project the ray of a point into camera space.

• Project to image plane by projective transform.

• Linear initialization and non-linear optimization.

Camera Geometry(Pinhole Model)

Image Registration

• Rely on pinhole model.

• Project the ray of a point into camera space.

• Project to image plane by projective transform.

• Linear initialization and non-linear optimization.

y

x

z

f

v

u

'

'

0

0

0

Z

Y

X

Z

Y

X

A33A32A31

A23A22A21

A13A12A11

z

y

x

0

0

'

'

v

u

vD

uSD

v

u

v

uu

Coordinate Transforms

Regional Geology

Study Site

2D Map View

Perspective View of Surveyed Points

Terrain Surface

Photo Reflector

F (mm) Std. Error

K1 K2 P1 P2

Photo1

No 23.1102 2.43 2.88e-5 -5.25e-7

-4.03e-4 4.73e-4

Photo2

No 23.8787 2.41 -2.17e-4 -2.80e-7

1.60e-4 5.62e-4

Photo3

Yes 23.5933 1.45 -5.54e-4 1.55e-6 -3.92e-5 -4.99e-4

Photo4

Yes 23.1816 0.63 -5.23e-4 1.17e-4 2.35e-6 -1.52e-4

Photo5

Yes 23.1962 0.72 -5.5e-4 1.46e-6 -5.87e-5 1.45e-4

Result of Image Registration

Control Points

Photo Mosaic

Reproject The Bed And Faults Onto Image

Photorealistic Outcrop

Photorealistic Outcrop

Re-Digitized Key Beds and Faults

Interpolated Subsurface

Interpolated Subsurface

A Cross Section From The 3D Model

Photorealistic Virtual Outcrop

Photorealistic Virtual Outcrop