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Figure 1. A granite false-door of Amenhotep II, as discovered 
in 1939 and the same in 1985 
To counter this progressive and irremediable annihilation of the 
material remains of the Past, Archaeology uses different 
recording techniques. Contrary to a quite general opinion, 
photography cannot ideally fulfil the purposes of the recordings 
needed by Archaeology and Art History: it always privileges 
one single plane of view, reducing the volume of the objects to 
a 2D picture; thus, it often introduces some distortions (mainly 
optical ones); it does not allow interpretative notation which 
might help its reading; and, finally, the results of traditional 
photography fade with time (silver halide emulsion, slide and 
paper copy). Therefore Archaeologists and Art Historians 
usually rely upon different complementing techniques of 
recording by drawing, but all these graphic techniques have a 
common rather poor flexibility in their management and their 
set up, and, also, an unavoidable dependence on the subjectivity 
of reading and rendering of a human operator (Traunecker, 
1987; Loeben, 1996). In order to preserve a minimum of 
accurateness, these drawing recordings are usually very slow,- 
and thus very expensive,- a fact that gives rise to a real race 
against time and the damages it can cause to historical 
monuments exposed to modem pollution (physico-chemical and 
tourist pollution). So recording in Archaeology and Art History 
raises two essential problems, related one to the other: on the 
one hand, the objectivity, and on the other, the speediness and 
the flexibility of realisation. 
3. THE SOLUTIONS OFFERED BY NUMERIC IMAGE 
AND OPTOELECTRONIC TECHNOLOGIES 
To overcome these inherent constraints of the traditional 
recording techniques, it is necessary to use new technologies of 
recording, processing and storing the data which define the 
precise 3D shape of any archaeological object, and also the 
associated thematic information (texture, color and structure 
that are not only defined by the shape of the object...) present on 
a photographic acquisition of it. So the solutions to the above 
described problems will evidently come from the field of 
Archaeometry, the use of scientific laboratory techniques to 
investigate remains of the Past in an historical and 
archaeological perspective. 
Nowadays, numeric image technology offers an almost infinite 
flexibility of use, with which traditionnal drawing techniques 
cannot compete. And, unlike photographic images, digital 
pictures do not suffer any natural damage that compromise their 
"life time". Moreover, recent developments in Optics and 
Optoelectronics allow now a real global 3D recording, in the 
same time faster and more reliable. Coupling these new 
technologies gives enormous advantages regarding the 
flexibility and the easiness of recording, processing, reading and 
storing; it also offers the possibility to imagine new ways of 
publishing ancient monuments, in an electronic form, more 
realistic, more accurate and more interactive, as a real 3D 
structure and not anymore by means of fixed and inaccurate 2D 
images. 
4. THE AVAILABLE TECHNIQUES 
There exist a few projects of global scanning of ancient artefacts 
(Clarke, 1998; Taubes, 1999). They reveal the existence of 
technological solutions to the fundamental problems raised by 
the recording of archaeological and monumental heritage. But, 
until now, none of the already available scanning devices is able 
to work in real in situ conditions (for example under the 
sunshine of Egypt), on large scale, and with the precision 
needed for archaeological and art historical research. So above 
all, they are some kind of laboratory apparatus, very difficult 
and often impossible to use in normal archaeological context, 
that is on site and on large scale. Thus the problem is still 
unresolved. 
Optical recording of the relief or the 3D shape of an object can 
be achieved by using two principles: the stereoscopy and the 
triangulation. 
The first one, stereoscopy, requires, as its name tells, two views 
of the same object but taken from different points of view 
(stations). Using the parallax deformations, it is possible to 
reconstruct the examined object in 3D. This very well-known 
principle is amply used by human vision and is the basis of 
photogrammetry. Some preliminary researches made by the 
Department of Geomatics of the University of Liège (notably in 
the SURFACES Laboratory [Service Universitaire de 
Recherches Fondamentales et Appliquées en Cartographie et 
Etude Spatiales ; dir. Pr J.-P. Donnay], in close cooperation 
with the ICAUL [Interdisciplinary Center for Archaeometry of 
the University of Liège; dir. Pr D. Allart; project dir. Dr 
D. Laboury]) have shown that it is possible to find a solution to 
the recording problem of Archaeology and Art History with 
digital photogrammetry. The project aims to develop a 
photographic set-up conceived in order to present a certain 
flexibility and an easy handling which will unable the 3D 
numerical recording of archaeological objects through a 
terrestrial photogrammetric treatment in almost any in situ 
conditions. It’s a three steps process applied to stereographic 
pairs of digital photographs: internal orientation based on 
camera calibration data, relative and absolute orientations, that, 
in this specific case, can be trained and validated using accurate 
topographical survey data. These steps are completed by an 
automatic matching algorithm. It allows the production of a 3D 
grid model that can be used to orthorectify the digital picture of 
the sensed object. The accuracy of the 3D model and the one 
shot recording area depend on the optical characteristics of the 
camera and the camera-object distance. The tests performed 
have produced a 0.3 mm precision model of a lm 2 area. So, the 
coregistred thematical (texture, color and structure that are not 
only defined by the shape of the object) and geometric