Diagnostic morphometric applicability of confocal laser scanning microscopy in Osteoarchaeology

The confocal laser scanning microscope (CLSM) has become an essential tool for a wide range of biological and clinical studies and imaging applications. The major imaging modes of the CLSM include single and serial optical sections from thick specimens (100 µm), multiple wavelength images and three‐dimensional reconstruction. Such images provide measurement of length, surface or volume of objects. Surprisingly, this advanced microscopic method has been very rarely used in anthropological research, although numerous clinical and basic science research projects showed its value to study, bone growth, bone micro‐architecture and 3D bone morphometry. We present the basic principles and advantages of CLSM and outline practical aspects of specimen preparation, image collection and digital image processing specifically appropriate for historical bone and hair material. Copyright © 2009 John Wiley & Sons, Ltd.     

Elk Heads at Sea: Maritime Hunters and Long‐Distance Boat Journeys in Late Stone Age Fennoscandia

Tumlehed is the most well‐preserved and complex prehistoric rock painting in the coastal region of south‐west Sweden. Originally reported and described in 1974, we re‐documented the panel using digital and IR photography, DStretch image enhancement software, and non‐destructive PXRF spectroscopy. This re‐documentation revealed a more complex image inventory with several previously unknown motifs and image details. The new data provide a better basis for identifying motif categories, the organization of the panel, the chronological sequence, and different frequentation periods. We report on the only known boats with an elk‐head stem in southern and western Scandinavian rock art, the emergence of rock art boat depictions in the region, and evidence for long‐distance maritime journeys and sea‐mammal hunting in the later Stone Age. Comparisons to similar images with shoreline data in Fennoscandia narrow the time range for the date of the painting to 4200–2500 BC.     

Documenting Archaeological Mortuary Features using High Dynamic Range (HDR) Imaging

This technical note presents a refined technique for photo‐documenting archaeological mortuary features using High Dynamic Range (HDR) imaging. Mortuary features in archaeological context can be complex and delicate given the wide variability in grave constructions and preservation of human skeletal remains. It is therefore critical to obtain the greatest detail possible when photo‐documenting these features. HDR techniques represent more contrast in photographs and provide greater detail across the DR of illumination within mortuary features—where complex arrangements of human remains can obscure or darken other elements or associated funerary objects, making them difficult to identify in traditional photographs. HDR can be employed with most standard digital single lens reflex cameras used for archaeological field projects, is easy to learn and employ (as described here), can be processed and produced with commonly used photo editing programs, and is ideal for use in unpredictable conditions that are often encountered with archaeological mortuary features and in field conditions. Copyright © 2013 John Wiley & Sons, Ltd.     

Representing financial inclusion: The CGAP microfinance photo contest (Respond to this article at http://www.therai.org.uk/at/debate)

This article examines representations of financial inclusion through the lens of the CGAP microfinance photo contest. It situates the contest's winning images within current contestations surrounding global financial inclusion strategies, to show how these photos construct particular representations of microfinance that legitimize CGAP's minimalist, commercially‐driven model. The production of the need for large‐scale financial inclusion is key to this model, which is depicted through gendered representations of microfinance beneficiaries. On the one hand, the CGAP photos present a shift from stereotypical images of female micro‐entrepreneurs in traditional contexts to more complex images that disrupt such stereotypes while at the same time reinforcing other assumptions about microfinance. On the other, they bring men back into the picture as worthy microfinance recipients. While contributing to pluralist representations that valorize photography in developing countries, the CGAP microfinance photo contest is ultimately unable to portray the complexities and contradictions of financial inclusion interventions.     

The Use of Optical Coherence Tomography for Monitoring the Subsurface Morphologies of Archaic Jades

We demonstrate the use of the Optical Coherence Tomography (OCT) technique for non‐invasive scanning of the subsurface morphologies of jade objects. The two‐dimensional tomography images show the refractive index or dielectric constant variations in the samples, reflecting their structures. Three samples of archaic jade objects from the Qijia and Liangzhu cultures in China are scanned in order to understand the subsurface morphologies of the naturally whitened jades. Also, two jade objects with artificial treatments (burning) are scanned and compared with the original materials in subsurface structures. In the original objects, the jade materials can generally be quite transparent, such that the backscattering intensity is weak, although the large‐scale (tens of microns or larger) subsurface morphology can be clearly observed. After burning, small‐scale (smaller than a few microns) structures are formed and the backscattering intensity is enhanced. In this situation, the large‐scale structures may be preserved or even newly generated. On the other hand, in an archaic object with natural whitening, small‐scale structures are also formed. Hence, the deeper distributions of significant backscattering intensity are observed, when compared with the unwhitened objects. Nevertheless, the large‐scale features diminish during the whitening process. With OCT scanning, such differences in subsurface morphology can provide us a valuable reference for authenticating archaic jade objects.     

Towards a Best Practice for the Use of Active Non‐contact Surface Scanning to Record Human Skeletal Remains from Archaeological Contexts

Active surface scanners emit light or a laser stripe to record the exterior surface of an object or landscape, providing results in three dimensions. The use of active surface scanners to record anthropological and archaeological contexts has increased within the last few years, creating a number of sub‐contexts within these disciplines and allowing a further development of certain applications, such as quantitative analysis, the use of replicas in education and museums and the creation of digital databases archived in institutions. However, with guidance, this paper aims to assess the advantages and disadvantages of active surface scanning and the potential for research with regard to the recording and analysis of human skeletal remains. The key advantages and uses identified include quantitative digitisation, geometric morphometric studies, conservation, preservation, documentation and reconstruction. However, surface scanning also has some limitations, including cost, technological expertise, the need for a power source, computing requirements and data size. Overall, the application of active surface scanning technology to archaeological skeletal remains will provide a vital digital archive that will serve to preserve the integrity of this fragile and finite resource for future generations. This is particularly important within the current developer‐funded environment in which many skeletal collections, including those yielding unique or unusual pathological or morphological features, are re‐buried, with only very limited time for analysis. Copyright © 2017 John Wiley & Sons, Ltd.     

文物三维数字化设计及其实验方法研究

文化遗产的数字化设计为文化遗产的保护、传承和利用提供了新的方法。针对文化遗产的数字化设计理论和方法,研究了文化遗产的三维数字化设计关键技术,构建了基于计算机辅助的三维扫描文物数字化重建方法,提出二维图像标定的三维网格纹理映射思路。通过商晚期出土的青铜牛尊文物三维数字化实验,完整地构建了文物数字化设计流程框架,并对文物数字化设计理论和方法进行验证。     

文物CT图像伪影校正方法研究

计算机断层成像(CT)技术具有不受工件材质限制、分辨率高等优点,可以在不损坏物体的前提下获取其三维数字化信息,因此在文物数字化领域具有广阔的应用前景和巨大的发展潜力。然而在CT扫描与图像重建过程中存在系统几何参数偏差与射线硬化等问题,会导致扫描图像质量下降、文物数字化模型的精度受限。本研究针对上述问题,提出了基于扫描数据的参数校准以及硬化校正算法,并对两件文物仿制品进行了CT扫描实验。实验结果表明,经过本研究方法处理后,扫描图像质量明显提升,重影和伪影现象得到了有效抑制,重建得到的数字化模型能清晰完整地还原文物形貌。该方法可被广泛应用于文物CT数字化工作中,有利于文物的复制、保护、展示以及文化的交流传播,具有较强的科学意义和社会经济意义。     

From Hand Survey to 3D Laser Scanning: A Discussion for Non-Technical Users of Heritage Documentation

Abstract

Digital technology has changed our approaches to cultural heritage documentation radically and promises to continue to bring rapid changes. Photographic and non-photographic (graphic) documentation tools are merging in one process, in which digital photographic technology is the main base. Due to digital technology, there is an increasing gap between specialist technicians and non-technical users involved in heritage documentation. 3D approaches are still not popular among users in cultural heritage. However, in order to build a bridge between the specialist and non-technical users, a dialogue between them needs to be developed, not only to discuss issues of data precision and 3D accuracy, but also visualization production systems, which can now easily be achieved by modern digital photographic technology.

This paper presents a comparative evaluation and synthesis of cultural heritage documentation methods and survey techniques currently available, focusing on the needs and requirements of non-technical users of heritage documentation. It attempts to clarify some new aspects in cultural heritage documentation and to assess the impact of current technology. The paper undertakes a comparative evaluation of the potential application of digital methods in documentation — and examines issues such as quality, accuracy, time, costs and specific skills required — from pre-electronic techniques (hand measurement) to 3D laser scanning, which today represents the most advanced technology available for measuring and documenting objects, structures and landscapes.     

ANALYSIS OF TRADITIONAL HISTORICAL CLOTHING: AUTOMATED PRODUCTION OF A TWO‐DIMENSIONAL PATTERN*

A recurrent problem for scholars who investigate traditional and historical clothing is the measuring of items of clothing and subsequent pattern construction. The challenge is to produce exact data without damaging the item. The main focus of this paper is to present a new procedure for establishing a three‐dimensional model and the corresponding two‐dimensional pattern for items of skin clothing that are not flat. The new method is non‐destructive, and also accurate and fast. Furthermore, this paper presents an overview of the more traditional methods of pattern documentation and measurement. Their weaknesses and strengths are also assessed.     

数字近景摄影测量在秦始皇陵百戏坑考古中的应用研究

既要保留遗迹在不同阶段的信息资料,又不影响发掘研究工作的继续进行,一直是考古工作者探索研究的问题。为配合秦始皇陵百戏俑坑的考古发掘工作,为后续考古研究和文物遗迹的保护提供必要的基础信息资料,针对大场景考古发掘现场,通过数字全站仪对文物挖掘现场布设的一定数量控制点进行观测获取其三维点位坐标。利用非量测数码相机获取现场多航带序列影像,通过数码相机检校、自动空中三角测量、影像特征提取与影像匹配、数字微分纠正等数字近景摄影测量方法,获取反映发掘现场文物分布情况的数字高程模型(DEM)和正射影像(DOM)数据。在生成的正射影像图上进行文物轮廓线条的提取,获得发掘现场文物的正射投影矢量图。实现文物位置、形状及分布的平面量测。实验证明:该方法不仅可大面积、快速获取文物挖掘现场文物分布的正射投影平面图,实现考古数字制图,而且能保证一定的精度。具有较高的推广应用价值。     

Deformation of Ancient Buildings inferred by Terrestrial Laser Scanning methodology: the Cantalovo church case study (Northern Italy)*

The study of the health of a building connects humanistic and scientific research, and a complete characterization can be achieved by integrating all the available historical documentation, architectural and metrological studies, as well as laboratory and in situ analyses of the materials. A contactless, non‐invasive surveying technique such as terrestrial laser scanning (TLS) allows the acquisition of dense and accurate geometric and radiometric (electromagnetic measurements such as signal intensity) information about the observed surface of the building, which can be easily integrated with data provided by high‐resolution digital imaging. The early Christian Cantalovo church was surveyed for the first time in April 2011, by means of the ILRIS‐3D ER very long range scanner. The second and last survey was performed in June 2012, after the main shocks of the Emilia earthquake seismic sequence. A very long range instrument is suitable for fast, simple and independent measurements, due to its technical characteristics and, for this reason, is easily usable for accurate surveying in emergency conditions. The main results are obtained by applying a data analysis strategy based on the creation of TLS‐based morphological maps computed as point‐to‐primitive differences, which allow the creation of a deformation map and its evolution in time.     

Weighted Bidimensional Regression. 加权二维回归

Shape analysis is useful for a wide variety of disciplines and has many applications. One of the many approaches to shape analysis focuses on shapes that are represented by predefined landmarks on an object. Some landmarks may be measured with greater precision, exhibit more natural variation, or be more important than others to an analysis. This article introduces a method for including this information when estimating mapping relations or assessing the degree of similarity between two objects that are represented by a set of two‐dimensional landmarks. Weighted bidimensional regression combines aspects of weighted least squares regression and bidimensional regression as a way to weight variables that are represented by a set of two‐dimensional spatial coordinates. One possible weighting scheme is suggested, and the effect of weighting is demonstrated through a face‐matching application. Results indicate that appropriate weighting increases the ability to correctly match two faces and that weighting has the largest effect when used with a projective transformation.     

Performance evaluation of a multi-image 3D reconstruction software on a low-feature artefact

Nowadays, multi-image 3D reconstruction is an active research field and a number of commercial and free software tools have been already made available to the public. These provide methods for the 3D reconstruction of real world objects by matching feature points and retrieving depth information from a set of unordered digital images. This is achieved by exploiting computer vision algorithms such as Structure-From-Motion (SFM) and Dense Multi-View 3D Reconstruction (DMVR). In this work, we evaluate the performance of a low-cost commercial SFM–DMVR software by digitising a Cycladic woman figurine. Although the surface properties of the specific artefact are considered 3D laser scanner friendly, its almost featureless white-grey surface composes a challenging digitisation candidate for image based methodologies as no strong feature points are available. We quantify the quality of the 3D data produced by the SFM–DMVR software in relation to the data produced by a high accuracy 3D laser scanner in terms of surface deviation and topological errors. We question the applicability and efficiency of two digitisation pipelines (SFM–DMVR and laser scanner) in relation to hardware requirements, background knowledge and man-hours. This is achieved by producing a complete 3D digital replica of the Cycladic artefact by following both pipelines.     

ORTHOIMAGE‐BASED DOCUMENTATION OF ARCHAEOLOGICAL STRUCTURES: THE CASE OF A MEDIAEVAL WALL IN PONTEVEDRA,SPAIN

During the completion of the expansion works at the Museum of Pontevedra (Spain), a stretch of about 60 m of the medieval walled enclosure surrounding the historic city centre was discovered. Due to its value as a heritage element, the discovery of this archaeological structure required the implementation of preservation activities and exhaustive documentation so that future generations will be able to know and enjoy this piece of history. This paper presents digital models that reproduce the original structure of the wall using close‐range digital photogrammetry, as well as orthophotos, which thoroughly document the dimensional and textural characteristics of the archaeological site. In addition to analysing the accuracy and validity of photogrammetry in the conservation of archaeological heritage, a methodology of data capture, processing and photogrammetry representation is evaluated.     

佛山石湾陶瓷艺术的数字化保护及利用研究

文化遗产和艺术作品的数字化保护与数字内容应用是近年来国内外文化界和科技界的一个共同研究热点,也是我国积极推动文化创新和文化产业发展的重要内容。为了更好地开展我国首批非物质文化遗产的佛山石湾陶瓷艺术的数字化保护工作,研究了非接触式光学三维扫描设备进行表面反光的陶瓷作品三维数据扫描和形态整合的问题。同时研究了利用HDR技术进行陶瓷表面色彩纹理信息采集和复原的技术方法,得到完整的陶瓷作品数字化模型,达到了对文化遗产数字化保护和数字内容建设的目的。最后,讨论和研究了文物数字化内容的宣传和推广方法,并给出了实际应用的案例。     

Digital heritage in a Melanesian context: authenticity,integrity and ancestrality from the other side of the digital divide

This article examines how digital heritage, in the form of 3D digital objects, fits into particular discourses around identity, ancestrality and cultural transmission in Melanesia. Through an ethnographic analysis of digital heritage use amongst the Nalik community in New Ireland (Papua New Guinea), it demonstrates how digital heritage is understood not in terms of deceit and a loss of authenticity, but instead, towards an understanding of authenticity in terms of completeness and integrity. A notion of completeness and integrity, I argue, has the effect of creating an authentic experience of the past for Nalik communities by bringing back museum objects (‘old’ objects) that have been dispersed amongst museums and heritage institutions worldwide. In tracing out the operations and effects of how a Melanesian community engages with 3D digital objects, this article offers unique ethnographic insights into digital heritage in ways that challenge widely-held assumptions about the heightened value placed on the original object over its digital counterpart.     

Towards a three-dimensional cost-effective registration of the archaeological heritage

Archaeological practice within the European context of heritage management is facing huge challenges in ways of recording and reproduction of ex-situ preserved sites. As a consequence of the Valletta-treaty, numbers of archived images and drawings of excavated structures as prime sources of past human activity, are exponentially growing. Contrarily to portable remains however, their future study and revision is biased by the two-dimensional character of the recorded data, rendering difficult their future reconstruction for new study or public dissemination. A more realistic three-dimensional (3D) way of recording and archiving should be pursued. In this paper the possibilities for 3D registration of archaeological features are examined in a computer vision-based approach using the PhotoScan software package (Agisoft LCC). It proved to be a scientific and cost-effective improvement compared to traditional documentation methods. Advantages can be found in the high accuracy and straightforwardness of the methodology. The extraction of an orthophoto or a Digital Terrain Model from the 3D model makes it feasible to integrate detailed and accurate information into the digital archaeological excavation plan. The visual character of 3D surface modeling offers enhanced output-possibilities allowing a better documentation of in-situ structures for future research and a higher public participation and awareness for the archaeological heritage.     

An Umm an‐Nar culture stone bas‐relief from Al‐Qutainah,Sultanate of Oman

The Al‐Qutainah stone with its bas‐relief decoration was found in a secondary position, reused through time. The object is clearly a facing stone, originally part of an Umm an‐Nar period tomb, and was subsequently repeatedly reused for making new engravings. While working out the sequence of images it became clear that the very first image was a pair of human figures. This artwork is associated to grave architecture and therefore dates to the Umm an‐Nar period. Two models of interpretation can be suggested, the image of a human pair or the image of a supplicant and deity. Changes in the original meaning of the image indicate conceptual changes in subsequent periods, most probably alterations in the underlying social structure. The importance of the Qutainah stone is not solely due to rare monumental human figurative expression of the period in Oman; furthermore, the find spot in the Adam region is at a distance from the central location of Umm an‐Nar culture that has so far emerged.