Calibration of Digital Image Analysis Protocols for Archaeological Ceramics

在国家科学基金会的支持下，钱德拉·里迪博士和特拉华州大学的一个跨学科学生团队将开发和测试使用廉价光学显微镜的新程序，以更好地了解陶瓷，这是最具考古意义的材料之一。他们将使薄片岩相学技术现代化，该技术使用安装在载玻片上的小样品并研磨至30微米厚。当在显微镜下用偏振光检查时，这些样品中的矿物可通过光学性质识别。薄片岩相学用于表征考古陶瓷，并调查陶瓷生产，功能，交换，技术风格和使用历史。然而，由于一些挑战，该技术往往被边缘化。例如，从薄切片获得定量数据的传统方法非常耗时，但仅使用定性数据限制了有用性。数字图像分析具有缓解这些问题的潜力。然而，一些基本的实验工作，首先需要与实验室制备的已知组成的标准。为了确保可靠性的考古陶瓷的分析未知的原始配方，协议首先必须进行测试的准确性与实验室制备的标本具有已知的成分，大小和数量的添加剂，并在已知的条件下烧制。本研究的主要重点，然后，是校准协议的数字图像分析薄切片偏光显微镜下观看。其他实验将使用通过在低放大倍数下扫描整个薄切片获得的图像。优点是这些图像包括薄片的整个区域，而不是像显微镜下那样仅包括单个视场，从而促进宏观纹理研究。一些探索性工作还将涉及碎片本身的数字图像，以获得补充薄片研究的定量数据。其优点是，无需进行薄片切割、镶嵌和研磨，从而可以在更大量的样品上收集数据，以快速表征碎片的某些特征。对于所有这三种方法，使用实验室制备的样品作为已知标准对于开发可靠的协议至关重要。在研究的最后阶段，协议将适用于考古标本，已经很好地表征了相关的比较分析技术。将完成的协议应用于考古样品将允许编辑，细化，并在需要时更清晰的解释，使协议更广泛地使用和reproducible.The这项研究的智力价值是，它将导致新的，现代化的定量偏振光显微镜的陶瓷程序。这项研究的更广泛的影响是，陶瓷材料在世界各地的考古遗址中被发现。这些材料代表了广泛的功能对象，并作为了解过去的许多文化问题的重要标志。这项研究将为分析和理解这些材料的新方法提供基础，以便更充分地探索有关人类过去的问题。来自多个学科的学生将参加该项目，以提高他们的实验室培训和跨不同领域合作的能力，同时增加他们对陶瓷的知识，陶瓷是人类历史上最重要的文化材料之一。

With National Science Foundation support, Dr. Chandra Reedy and an interdisciplinary team of students at the University of Delaware will develop and test new procedures for using inexpensive light microscopes to better understand ceramics, one of the most archaeologically-significant classes of materials. They will modernize the technique of thin-section petrography, which uses small samples mounted on a glass slide and ground down to 30 microns thick. When examined under a microscope with polarized light, minerals in such samples are identifiable by optical properties. Thin-section petrography is used to characterize archaeological ceramics and investigate ceramic production, function, exchange, technological style, and use history. However, the technique is often marginalized because of some challenges. For example, traditional methods of obtaining quantitative data from thin sections are very time consuming, but using only qualitative data limits usefulness. Digital image analysis has potential to alleviate these problems. However, some fundamental experimental work is needed first with laboratory-prepared standards of known composition. To ensure reliability of analyses of archaeological ceramics of unknown original recipes, protocols first must be tested for accuracy with laboratory-prepared specimens having additives of known composition, size, and amount, and fired under known conditions.The primary focus of this research, then, is to calibrate protocols for analysis of digital images of thin sections viewed under a polarizing microscope. Additional experiments will use images obtained by scanning whole thin sections under low magnification. An advantage is that these images include the entire area of the thin section rather than just a single field of view as under a microscope, facilitating macrotexture studies. Some exploratory work also will involve digital images of sherds themselves, to obtain quantitative data that supplements thin-section studies. An advantage is that the time and expense of thin-section cutting, mounting, and grinding are eliminated, allowing data to be collected on even larger numbers of specimens for rapid characterization of some features of a sherd.For all three of these approaches, using laboratory-prepared specimens as known standards is crucial for development of reliable protocols. In the final phase of research the protocols will be applied to archaeological specimens that have already been well characterized by relevant comparative techniques of analysis. Applying the finished protocols to archaeological samples will allow editing, refinement, and clearer explanations where needed so that the protocols are more widely usable and reproducible.The intellectual merit of this research is that it will result in new, modernized procedures for quantitative polarized light microscopy of ceramics. The broader impact of the study is that ceramic materials are found at archaeological sites throughout the world. These materials represent objects of a wide range of functions and serve as important markers for understanding many cultural issues about the past. This research will provide the basis for new methods of analyzing and understanding these materials, so that questions about humanity's past can be explored more fully. Students from several disciplines will participate in the project to enhance their laboratory training and ability to work together across different fields while increasing their knowledge about ceramics, one of the most important cultural materials in human history.