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.     

高光谱成像技术在中国古代书画分析中的应用研究综述

中国古代书画，因其年代久远，递藏情况复杂，多数屡经裁切割补、修复重装，故而有很多历史信息或被叠摞或被遮蔽，导致今人不能以肉眼直接观察而获得，而纸绢接补，墨迹、颜料、印鉴的残损也为书画研究者带来诸多悬而未决的问题。近年来，高光谱技术作为一种非侵入式的光谱成像技术，已逐步应用于各类彩绘文物中，该技术可为中国古代书画研究和保护提供更丰富的信息。本工作以文献调研为基础，简要介绍了高光谱成像的原理及技术特点，对高光谱技术在中国古代书画研究的实践进行总结，梳理了国内外研究者利用高光谱技术在书画、档案及相关彩绘文物的增强显示、物质识别、虚拟修复方面的应用案例，以期为相关研究者提供参考借鉴。     

Mapping of the Buried Yarmouth Roads Wreck, Isle of Wight, UK, using a Chirp Sub-Bottom Profiler

Remains of the 16th-century Yarmouth Roads wreck, buried in sediments, were imaged using high-resolution geophysical techniques. The remains appear as strong reflectors underlain by an acoustic blanking zone, which was used to create maps of the wreck material. Close survey line-spacing allowed the construction of contour maps and hull sections, which revealed that the bow and stern sections are tilted to port at different angles, implying that they are detached. The seismic data have enhanced our understanding of the site beyond what was known from conventional archaeological investigations and confirms that this wreck was once a large carrack.
© 2007 The Authors     

Chemical analyses of the earliest pigment residues from the uttermost part of the planet (Beagle Channel region,Tierra del Fuego,Southern South America)

This paper presents the results of chemical analyses of the organic and inorganic fractions of pigment residues found in three archaeological sites located in the Beagle Channel region, Tierra del Fuego, Southern South America. Twenty-one archaeological samples have been analysed through XRD, SEM–EDX, FT-IR and GC–MS in order to characterise their inorganic colouring components and to search for the presence of organic substances used as binders. Lipids found in some samples are considered as potential binders. These organic components are compared to those found in archaeological sediment samples from the same layers where the pigments have been found, in order to search for potential taphonomic contaminations of the latter by the former. Results show that such contaminations are unlikely, hence the lipid contents are deemed of anthropic origin. The pigment sample results are also compared to data from analyses of natural sediment samples collected in several localities of the Beagle Channel in order to search for potential natural pigment sources. Results show that organic and inorganic components of these sediments are not the same than those present in the archaeological pigment samples, hence the pigment raw material sources have not been yet located. All these data provide for the first time evidence of the existence of ancient activities of pigment sourcing and paint preparation with organic binders which range from 6000 BP to 1900 BP in the southernmost region of the planet.     

The digital restoration of painted patterns on the No. 2 Qin bronze chariot based on hyperspectral imaging

The No. 2 Qin bronze chariot unearthed from Qinshihuang's Mausoleum is world famous for its huge size and colourful painted patterns. However, since it had been buried for a long time and was affected by its harsh environment, its painted patterns have been severely damaged. The traditional restoration methods, which mainly rely on expert experience, are manual, inefficient and lack scientific support. Moreover, to protect the important cultural relics, any invasive operations, such as sampling analysis, are strictly prohibited. This paper presents a method that combines hyperspectral imaging and computer technology for the digital virtual restoration of the bronze chariot's patterns. It is non-destructive, more efficient and more scientific. The method reproduces the damaged patterns with the following approaches: restoring the missing edges of the patterns; and distinguishing the different pigments. The obtained result implies that the method can digitally reproduce some of the damaged patterns, and that it can be used as a reference for recreating the patterns of the other painted bronze.     

CT imaging of human mummies: a critical review of the literature (1979–2005)

The number of computerised tomography (CT) investigations of mummies has increased since the first published study in 1979. However, this approach has never been validated. We present a critical analysis of the literature (1979 to 2005). Relevant articles were selected via a MedLine search and analysed according to CT technique, methodology, and author's speciality. Thirty‐one original articles matched our selection criteria. Of these studies, 42% were authored by radiologists, while 26% had no contribution from radiologists. Hypothesis‐driven papers comprised only 9.7% of the total. While 84% of the studies had a stated purpose for conducting the CT study, only 67% of studies defined their CT protocol clearly. CT was used to study mummification techniques in 74% of instances, and/or to detect disease in 58%. Conclusions based on CT analysis were derived in 84% of studies, but only 32% of these answered specific questions. Furthermore, only 36% of these conclusions were related to the stated purpose of the study. Using the criteria of the grading system we developed, we found that 61% of studies were supported only by weak evidence. We conclude that evidence‐based research with better design should be encouraged in future palaeoradiological studies. Copyright © 2008 John Wiley & Sons, Ltd.     

Optical Coherence Tomography for the non-invasive investigation of the microstructure of ancient Egyptian faience

Optical Coherence Tomography (OCT) is a non-invasive subsurface 3D imaging technique based on the Michelson interferometer. The non-invasive nature of OCT and its speed of acquisition makes it possible to image large volumes of intact objects to yield a complete overview of the microstructure. The production methods for ancient Egyptian faience were first investigated using scanning electron microscopy (SEM) imaging of the microstructure in polished sections and microprobe analysis of the composition of the glass phases. These studies were based on original Egyptian faience objects and laboratory reproductions of faience beads made using three different production methods. The microstructure of the same laboratory samples and the Egyptian faience objects from the British Museum Research Laboratory Collection are re-examined using OCT. It is found that OCT virtual cross-section images can be used to group ancient faience objects into three categories on the basis of the morphology of the surface glaze layer and the glaze/core interaction layer. The OCT images correspond well with SEM images of polished sections of ancient faience objects and laboratory reproductions. The virtual cross-sections produced by OCT are somewhat limited by the penetration depth, which is affected by the high absorption coefficient of the material and, therefore, cannot always provide information on the presence or absence of interparticle glass that binds together the quartz particles in the core. Nevertheless, the top two layers are well imaged and since OCT images can be obtained rapidly and without the necessity of removing a sample, the method can be applied to a very much wider range of ancient faience objects than is possible by SEM examination of polished cross-sections. In summary, this paper examines to what extent OCT can assist the investigation of the production techniques of ancient Egyptian faience.     

Use of Computed Tomography and Three‐Dimensional Virtual Reconstruction for the Examination of a 16th Century Mummified Dog from a North German Peat Bog

The corpse of a well‐preserved dog was recovered from a peat bog in the region of Burlage, Germany, in 1953. The dog, which dates to the 16th century, retained extensive soft tissue and fur on the postcranial body, although the head is skeletonised. Computed tomography was used to determine the extent of the preservation of the soft tissue, to determine sex and age and to attempt to identify trauma, pathology and potential cause of death. The analysis of the CT data indicated that the dog was an immature or adolescent male. Substantial soft tissue was preserved, including some internal organs. The entire skeleton was present, with the exception of the mandible and parts of the paws; all of the bones were flattened and some were distorted because of demineralisation in the peat. Partial disarticulation of the vertebral column was postmortem, although there was no further evidence of trauma or pathology on the skeleton or soft tissue. The cause of death could not be conclusively determined. To the knowledge of the authors, this dog represents the only known example of a complete historical nonhuman bog body with preserved soft tissue. Copyright © 2011 John Wiley & Sons, Ltd.     

基于光谱成像的彩绘文物新应用与新方法

目前基于光谱成像的彩绘文物分析主要集中在颜料分析、信息增强、隐含信息挖掘等方面,分析方法主要采用遥感图像处理软件。针对文物数据专门分析方法研究尚显不足的问题,提出基于光谱成像的彩绘文物新应用与新方法。主要包括基于最小噪声分离(MNF)变换感知修复区域的新应用,利用感兴趣区域分析与融合挖掘彩绘文物隐含信息以及基于稀疏非负矩阵欠近似彩绘文物线稿提取的新方法。通过在唐墓壁画、彩绘泥塑以及手绘绢画上的实验,发现光谱成像可以有效感知修复区域,提出的新方法可以有效挖掘隐含信息以及提取线稿,对基于光谱成像的彩绘文物分析研究具有重要意义。