Computer vision methods and rock art: towards a digital detection of pigments

A non-invasive procedure for assessing and interpreting the pigments of rock art paintings through computer vision and photogrammetric techniques is presented. The method is designed to document and interpret poorly preserved pigments by making use of advanced techniques of photogrammetry and computational imaging. Two different software solutions that were developed by the authors have been used for this purpose. Finally, two case studies of rock art paintings from Spain have been analysed, which show the reliability of the method.     

Latest developments in rock art recording: towards an integral documentation of Levantine rock art sites combining 2D and 3D recording techniques

This paper presents a further step in the integral documentation of prehistoric rock art, combining 2D and 3D digital recording techniques. Image processing and digital enhancement techniques are an invaluable aid to obtain high quality and accurate 2D recordings, especially when working with faint motifs or complex superimpositions. But what constitutes a real breakthrough is the possibility of combining 2D digital tracings with metric 3D models, providing a whole set of metric outputs that improve our understanding of the motifs in their context and, at the same time, can be used to deliver accurate metric reproductions.     

Ethics,politics and practices in rock art conservation

Abstract

Weathering and deterioration of Norwegian rock art has become an increasing area of concern over the last decade, with subsequent increasing efforts towards conservation. This has brought questions onto the agenda regarding the ethics and politics involved in conservation theory and practice. It is argued that such issues have been difficult to debate due to the concept of conservation being regarded as a legal and moral ideal. Referring the situation in Norway to ongoing global debates and perspectives regarding rock art conservation enables us to reveal and discuss some of the fundamental and complex philosophical issues involved. Notions of authenticity which implicitly underlie attitudes to rock art conservation are questioned, and the relationship between ‘green’ politics and rock art conservation is also discussed. A tendency towards uniform solutions and avoidance of critical issues, seen as influenced by strong social-democratic political traditions in Scandinavia, is at odds with the growing realization that most approaches to rock art conservation inevitably have unforeseen and frequently undesired consequences. Rather than further segmenting ethics, politics or practices in rock art conservation, a self-critical and reflective approach is suggested whereby changing concepts of ethics and authenticity are continuously debated.

Aucune loi ne pourra jamais préserver la sacralité d'un lieu … si ce n'est une loi morale, non écrite,adoptée et respectée par chaque individu, un véritable code personnel d'éthique.

(Soleilhavoup, 1994: 14)     

Boats in the rock art of Kanozero and Northern Europe

A comparative analysis of boats depicted in the rock art of Lake Kanozero and Northern Europe suggests that they refer to the same type, which was common in northern cultures and was characterized by a protruding straight keel, an oblique sternpost, and a stem post decorated with an elk head. The design apparently consisted of a broad keel plank to which the sides, bow, and stern were attached. In boats represented at Kanozero, this plank protrudes forward, beyond the nose, and backward, beyond the stern.     

Representation and knowledge in the prehistoric rock art of Africa

This study proposes that prehistoric rock art in Africa represents aspects of the natural and social environment which are aesthetically charged, for practical and symbolic reasons, and which are also problematic, in specific ways, for ordinary, untutored perception. Rock art functions as a medium of communication in three principal contexts. It refers to an extended network of ritual acts and beliefs, to out-of-the-ordinary perception and knowledge, and to adaptively significant local information. Rock art is therefore a particular, specialized instrument of the production process. Investigating the study of prehistoric art from art historical, archaeological, and anthropological points of view, the paper examines the ways in which the original contexts of function or meaning might be reconstituted, given the special nature and constraints of graphic representation as a mode of knowledge. Three major traditions of prehistoric rock art in Africa, the Sahara, Nile valley, and southern, are the focus of discussion and source of examples. The paper takes as a general theme the feasibility or possibility of an adequate archaeology of prehistoric knowledge.

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Résumé La présente étude propose que l'art rupestre préhistorique en Afrique représente des aspects du milieu naturel et social, exprimés de façon esthétique pour des raisons pratiques et symboliques, et qui présentent aussi des problèmes particuliers face à une perception non instruite. L'art rupestre sert de moyen de communication dans trois contextes principaux: il fait allusion à un réseau compliqué de croyances et d'actes rituels, à une perception et à des connaissances hors de l'ordinaire et à des renseignements locaux affectant l'adaptation. L'art rupestre figure donc comme instrument particulier et spécialisé dans le processus de production. En vérifiant l'étude de l'art préhistorique des points de vue historique, archéologique et anthropologique de l'art, l'article examine les façons selon lesquelles les contextes originaux de la fonction ou la signification pourraient être reconstitués, selon la nature et les contraintes spéciales de la représentation graphique comme genre de connaissance. La discussion se centre sur trois traditions principales d'art rupestre préhistorique, celles du Sahara, de la vallée du Nil et de l'Afrique du Sud, d'où sont aussi tirés les exemples. L'article a pour thème général la possibilité d'une archéologie mieux adaptée à la reconstruction des modes de connaissance préhistorique.

     

贵州省龙里巫山岩画的原始性艺术探析

岩画,是人类最早的绘画艺术,也是人类社会记录在石头上的形象性史书。贵州省龙里现存有丰富的岩画,它对研究贵州古代民族史、古代艺术史、社会生活史、动植物生态学、人类学及旅游开发等方面均有着极其重要的意义和非常高的学术研究价值。     

Expressions of fertility in the rock art of Bantu-speaking agriculturists

This paper presents an overview of the Late White rock paintings of south-central and southern Africa. It is argued that the most recent paintings were produced by matrilineal or bilateral Bantu-speaking agriculturists, although links with earlier hunter-gatherer groups are also implied. It is noted that certain motifs reoccur over great geographical distances. Ethnographic data are used in order to suggest a possible meaning for these motifs and for the paintings in general. It is argued that many of these paintings embody conceptual associations linking them to fertility. A general outline of the most obvious associations is presented, and a plea is made for detailed regional surveys in order to explain temporal and spatial differences.

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Résumé Cet article présente une vue d'ensemble sur les peintures rupestres Late White d'Afrique australe et du sud de l'Afrique centrale. Il défend l'idée que les peintures les plus récentes ont été produites par des agriculteurs matrilinéaires ou bilatéraux parlant le bantou, tout en supposant des rapports avec des groupes plus anciens vivant de la chasse et de la cueillette. On remarque que certains motifs réapparaissent à de grandes distances géographiques. L'article s'appuie sur des données ethnographiques pour suggérer une signification possible à ces motifs ainsi qu'aux peintures en général. Il démontre que nombreuses de ces peintures représentent des associations conceptuelles les associant à la fertilité. Un aperçu général des associations les plus évidentes est présenté et les auteurs demandent que des études régionales détaillées soient effectuées afin d'expliquer les différences temporelles et spatiales.

     

New tools for rock art modelling: automated sensor integration in Pindal Cave

This paper presents the integration of automated sensors based on a terrestrial laser scanner and an amateur digital camera with the aim of generating a photorealistic three-dimensional (3D) model of the Principal Panel in Pindal Cave (Spain). The approach developed for 3D modelling overcomes many of the problems related to the independent implementation of photogrammetry and laser scanning. Particularly, a sequential and hierarchical approach was developed based on the processing and matching of images from the camera (camera image) and the laser scanner (range image). The results obtained demonstrate that the workflow for this model is automatic, effective, and accurate. The presented approach was found to create hyper-realistic models, even improving upon human visual capabilities.     

Gender, representation, and power in San ethnography and rock art

Interpretation of San rock art has been heavily dependent on the various San ethnographies, particularly those of the /Xam, who inhabited the northern Cape Province, South Africa, until the early 20th century. A different reading of these ethnographies enables another avenue of interpretation: the interlinked themes of gender, sexuality, and rain appear to be as important in the art as shamanistic elements (reference to which has been a key development in understanding the art). While interpretation centering on the trance dance, recorded ethnographically from recent and contemporary San groups, has been most productive, many features of the art may be related to other aspects of San culture—to the female initiation ceremony, social organization, and the complex of notions and practices surrounding feminine gender and female sexuality.     

Acoustics and Levantine rock art: auditory perceptions in La Valltorta Gorge (Spain)

This article explores the relevance of acoustics as a factor for in the production and active use of Levantine rock art in Spain. The renowned rock art area of La Valltorta Gorge serves as a case study. Two experiments are described; the first assessed whether the sites with the most painted motifs had better acoustics than those with fewer motifs. The second tested which areas in La Valltorta Gorge had better acoustics and whether there was a difference between the acoustics of the decorated area and the contiguous sectors of the Gorge where no paintings have been found. In both experiments different sounds and pitches were used. The results suggest a strong relationship between the painted areas and the sonority of the place, with the major sites generally having provided the best results, with the exception of the sonority when facing the rock art panels. It is suggested that La Valltorta Gorge was chosen to be decorated with a view to increasing the perceptual impact of the rituals that may have been held at rock art sites due to the amplification caused by the echoing and resonance.