Methodological contest between high-end hardware and low-cost equipment for archaeological documentation

ugliestmysticAI and Robotics

Nov 14, 2013 (4 years ago)

137 views

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

Methodological contest

between high
-
end hardware and low
-
cost
equipment for archaeological documentation





keywords

structure from motion, image
-
based modeling approach, 3D geo
-
spatial field
technology, archaeological data acquisition, 3D laser scan, FOSS, GRASS GIS, high
resolution digital documentation technique

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz



Introduction


-
>



Aim



-
>



Case
study


-
>



Results



-
>



Outlook



-
>
Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


First
application

of

terrestrial

laserscanners

in
Prehistoric

Archaeology

by


VIAS

Wien

Quelle: VIAS Wien

©
VIAS

Vienna

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


First
application

of

terrestrial

laserscanners

in
Prehistoric

Archaeology

by


VIAS

Wien


ArcTron
)

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook

Advantages &
Disadvantages



-
High
quality

and

precise

documentation

-
immediate
control

-
Hardware: quick
and

easy
to

use

-
Software:
can

be

operated

intuitively

after an
introduction

-
Fast
and

easy
referencing

and

geo
-
referencing

possible

-
Fast
data

processing

=
data

preparation

-
Time
consuming

because

of

mostly

more

than

one

scanworld

is

needed

-
Every
scanworld

needs

a
new

registration

by

scanning

all
targets

= time
consuming

-
Hardware:
havy

equipment

-
Difficult

custum

regulations

in
certain

countries

-
Very

expensive
equipment

-
Software:
Very

expensive
proprietary

for

documentation

and

first

data

preparation

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


Computer Vision /
Structure
-
from
-
motion


-

originally

developed

for

Tourism

/
Social

networking

purposes

-

Online
-
Services
like

Photosynth

or

Photofly

for

all
all

kinds

of

use
:


private,
construction
,
forensics
, design…



-
> ca. 150
industries

using

it

(NY Times)




Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

Computer Vision /
Structure
-
from
-
motion



-

Adaption
for

archaeology

as

a
low
-
cost

alternative
to

laser

scanning

-

different
packages

available
:

-
Proprietrary
:
Photoplan
,
Arctron

aspect3D

-

Open
source
:
ArchOS
,
BundlerTools
,
VisualSFM

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook

Advantages &
Disadvantages



Advantages:


-

little

gear

-

low
-
cost

-

time
-
saving

(on
-
field
)

-

more

weather

resistent

-

flexible



Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

Disadvantages

-

spatial

cover

-

post
-
processing

(Workflow)

-

no

immediate

control

-

required

compute

power (but
no

cloud
-
computing

necessary
)!

-

georeferencing

Advantages &
Disadvantages



Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


Laserscanning

Structure
-
from
-
Motion

Hardware

Price

High

Low

Transport

Heavy
and

difficult

Just
one

photo

camera

ist
needed

Additional
Equipment

+ Tripod, + Notebook, + certain
targets

No

Power supply

Needed

Needed

Acquisition time

6x as long

as
SfM

Workflow
steps

distance, spatial cover

The
longer

the

distance
,
the

lower

the

resolution

.

field of application

Architectur
, Prehistoric

Excavation.

Weather sensibility

Not applicable by rain and
temperature higher

40
°
C and
lower


40
°
C.

Handling management

Difficult to handle

Software

Price

high

Usability

can

be

operated

intuitively

after an
introduction

Maintenance

Processing time

Post
-
processing

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


1. 489.381, 702.880, 2.747

2. 490.217, 701.778, 2.813

3. 488.992, 702.380, 2.844

4. 490.498, 702.327, 2.781

1. 489.376, 702.918, 2.725

2. 490.206, 701.811, 2.813

3. 488.969, 702.372, 2.857

4. 490.475, 702.319, 2.767

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


164 743
vertices


Laserscan

(
resolution

1 mm, 1
Scanworld
)

Structure
-
from
-
motion

238 247
vertices

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook




Taking

pictures
: easy




Taking

usable

pictures
,
some

things

to

think

of
:


Good

camera

objective

helps


large
memory

cards

necessary


Don
´
t

forget

targets

for

measurements

and

color

balance


more

cameras

would

even

speed

up


assure

the

overlap
!


Laptop on
site

for

instant check
of

photos

and

running

of

small

models

Data acquisition of structure from motion

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


Open
-
source
:
bundle

of

software

needed
:




Image
viewer
/Graphics
software


-
>
sort

/
rename

images




Linux:
BundlerTools





-
>
create

pointcloud




Meshlab
,
CloudCompare




-
> clean
pointcloud
, pick
points





NEW: GRASS GIS:

.
ply
-
Import/Export
module

+
georeferncing

(
rectify
)





Paraview
, (
AutoCAD
),
Meshlab
,
CloudCompare
, Blender

-
>
analyzing



Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

3D
Georeferencing

application flow:

1)

Import of the point cloud in different file formats: e.g. PLY, LAS

PLY Vertex
-
attributes included





v.ply.in

2)

Georeferencing

of vectors in GRASS GIS








v.transform

3)
Export of

the point
clould

in different file formats: e.g. PLY, VTK




v.ply.out


Maximum size of the
pointcloud
: 2 billion points

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

3D
Georeferencing

Affine and higher polynomial transformation

based
on control points


The accuracy of the

transformation is depended on
the accuracy of the
control points


Affine transformation:

For each dimension separately:
move, scale, rotate


Helmert
-
Transformation (coming soon!):

For each

dimension separately
: move, rotate

For all dimensions equally: scale

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz


Introduction


Aim


Case
study


Results


Outlook


Computer Vision /
SfM

(Open
-
source
)




Toolchain
from

digital
images

to

georeferenced

3D
-
model
available



Things
to

improve
:



Usability

of

software

packages




-

automatic

target

detection



Database
connection

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

Undine Lieberwirth, Bernhard Fritsch, Markus Neteler, Markus Metz

Co
-
operation between the


Excellence Cluster 264
-

TOPOI
Berlin/Germany

and

Fondazione Edmund Mach


Research and Innovation Centre

Trento/Italiy

THANK YOU FOR YOUR ATTENTION!