Muzeum Archeologiczne w Poznaniu [Hrsg.]: Fontes Archaeologici Posnanienses: Annales Musei Archaeologici Posnaniensis (48.2012)

Fontes Archaeologici Posnanienses
Vol. 48 Poznań 2012

Open software „HROT”. Digital 2D technology
for the description of archaeological analysis

Zdeńka Nerudoya1, Petr Neruda2, Petr Sadoysky3

Otwarte oprogramowanie “HROT”. Technologia 2D w analizie archeologicznej

Introduction

Various techniąues of visualisation and recon-
struction have accompanied archaeological rese-
arch for quite a long time. They allow to describe
an archaeological artefact with non-destructive
methods, to analyse or reconstruct and „mate-
rialize” it. If we want to obtain a set of data with
the highest possible objective level, or to obtain
data collected under the same conditions in case
of an analysis done on many artefacts (controled
data collection), it is advisable to use one rese-
arch method offered by modern technology. The
focus switches from classical methods (drawing,
painting and analogue photograph) to the use
of digital data to describe items and to objectify
obtained information. Nowadays a 3D scanner is
considered as the most up-dated option because
it offers complex documentation of the artefact
in question (Lambers et al. 2007 ; Grosman et al.
2008; Karasik, Smilanski 2008; Niven et al. 2009).

Processing of a 2D photograph may also bring
relevant conclusions for a shape analysis of the ar-
tefact. Thus oriented systems bear advantages of
relative simplicity and availability and they may be
effective and financially reasonable while solving
some special questions. One of the problems, which
might be solved by processing of a classical 2D pho-
tograph, was a morphological analysis of leaf points;
we carried it out within grant project.

The main goal was to obtain a high number of
data which could be statistically assessed; the metric
data were the most important but their collection
was rather time consuming. That was the reason to
obtain morpho-metrical data, to compile a complex
database and to carry out data processing using digi-
tal and computing equipment at the highest possible
level. We decided to develop a specialized softwa-
re named „HROT”. The program works with digi-
tal pictures consequently processed with a special
software. The software was created in cooperation
with the Faculty of Electrical Engineering and Com-
munication of Brno University of Technology.

A Computer Analysis of Leaf Point Morphology

The first step is to take front and side digital ima-
ges of each leaf point. Each photograph includes a
metric scalę (a square sized 10x10 mm)4. This squ-
are scalę allows to find out the size of a leaf point in
millimeters and it does not depend on the distance
of the camera from the leaf point.

The processing starts with transformation of the
picture from the colour RGB to gray scalę image.
The image is thresholded. Consequently the first
picture segmentation is carried out to separate the
scalę from the leaf point. To enhance the accuracy of
the scalę, two separate methods are applied and the-
ir results are used to calculate an average value. Due
to the fact the leaf point is always turned sidewards

1 Mgr. Zdeńka Nerudova, Ph.D., Moravian Museum, Anthropos Institute, Zelny trh 6, Brno, 659 37, Czech Republic, e-mail: [e-mail].

2 Mgr. Petr Neruda, Ph.D., Moravian Museum, Anthropos Institute, Zelny trh 6, Brno, 659 37, Czech Republic, e-mail: [e-mail].

3 Ing. Petr Sadovsky, Ph.D., The Faculty of Electrical Engineering and Communication of Brno Universityof Technology, e-mail: [e-mail].

4 In case of larger artefacts, it is possible to change the scalę manually in option “Tools”.