PISTACHIO: Photonic Imaging Strategies for Technical Art History and Conservation

我们的有形文化遗产，无论是历史上的还是当代的，都是由大量复杂的多层材料构成的。我们看到的往往只是物体的表面和形式。下面隐藏的是这些物品最初创造过程的材料和证据。通过使用最先进的成像/光谱系统，可以绘制成分并揭示其创作阶段，我们可以了解其原始背景和当今的意义和重要性。这是技术艺术史、考古学和物质文化研究等学科的核心。它还能为藏品的保护、获取政策和文化遗产的保护提供信息。红外成像和光谱学特别适合于观察物体表面以下的情况，因为通常可见光发生的散射要少得多，因此红外线可以更深入地穿透物体。根据材料及其结构，红外光将被吸收或反射。这可以直接成像或调制（傅里叶变换光谱）以获取指示化学成分的光谱信息。目前在文化遗产领域使用的大多数技术只能进行现场测量;绘制大面积地图需要数小时至数天的时间来获取数据，因此通常不可行或不适合现场测量。其他技术需要采集样本，因此是侵入性的。我们的目标是探索最先进的红外成像策略，将是“适合的工作”。这意味着宽带宽，全领域和快速技术与信号处理/光子学方法相结合，以分析，可视化和操纵大型多变量数据集。通过利用Heriot-Watt开发的最先进的激光源并提供大量可调谐红外光，我们将探索和开发几种用于4维成像的互补策略（3 x空间，1 x波长）。压缩传感照明技术和基于机器学习的数据处理将使我们能够快速有效地成像，同时通过自动分类表面和亚表面特征从数据集中提取最大价值。通过这种方式，我们希望为我们团队中的ICT和技术艺术史研究人员提供共享价值的成果。来自艺术史的背景信息将为我们部署的光子设计和计算分析策略提供信息，而强大的ICT技术将为技术艺术史社区提供新的技术能力，揭示以前隐藏的结构和历史。我们文化遗产对公众的重要性促使我们从一开始就整合外展活动，特别是一个使用4D数据的动态网站，提供一个互动工具，用于探索所选的案例研究，反映了ICT优先事项的核心。该项目包括工业合作伙伴，他们将提供中红外激光器的资源和专业知识（Chromacity Ltd.）和中红外照相机（Thales Optronics Ltd.）。我们的合作伙伴承诺提供大量实物支助，包括提供技术和贡献工作人员时间。此外，他们的参与确保了项目内的活动及其产生的成果可以迅速得到评估，以寻找邻近的商业机会。跨学科性是嵌入在ICT社区（光子学和人工智能技术研究人员）内的合作，并与AHRC资助的文化遗产社区的研究人员。共同创造是必不可少的：只有结合我们团队中每个研究小组的独特技术，背景和材料资源，该项目才能成功地提供红外成像和分析的新功能，以及对具有共同价值的文化重要对象的新见解。

Our tangible cultural heritage, both historic and contemporary, is made from a plethora of complex multilayer materials. What we see is often only the surface and form of an object. Hidden below are the materials and evidence of the processes by which the objects were originally created. By using state of the art imaging / spectroscopy systems which can map the composition and reveal the stages of their creation, we gain an understanding about the meaning and significance, both in their original context and our present day. This is at the heart of the disciplines of technical art history, archaeology and material culture studies. It also informs collections care, access policies and conservation of cultural heritage.Infrared imaging and spectroscopy is particularly well suited to looking below the surface, as the scattering which normally occurs with visible light is usually much less. Thus the infrared penetrates further into the object. Depending on the material and its structure the infrared light will be absorbed or reflected. This can either be directly imaged or modulated (Fourier Transform Spectroscopy) to acquire spectroscopic information indicating the chemical composition. Most techniques employed at present within the field of cultural heritage can only make spot measurements; to map large areas would take hours to days to acquire the data and therefore is not usually viable or suitable for in-situ measurements. Other techniques require samples to be taken and are therefore invasive. We aim to explore state of the art IR imaging strategies that will be "fit for the job". This implies wide bandwidth, full field and fast techniques coupled with signal processing/ photonics methods to analyse, visualise and manipulate large multivariate data sets. By exploiting state-of-the-art laser sources developed at Heriot-Watt and providing massively tunable infrared light, we will explore and develop several complementary strategies for 4-dimensional imaging (3 x spatial, 1 x wavelength). Compressive sensing illumination techniques and machine-learning based data processing will allow us to image rapidly and efficiently while also extracting the maximum value from our datasets by automatically classifying surface and sub-surface features.In this way we expect to produce outcomes of shared value for both the ICT and Technical Art History researchers in our team. Contextual information from art history will inform the photonic design and computational anaylsis strategies we deploy, while powerful ICT-led techniques will provide the Technical Art History community with new technical capabilities that reveal previously hidden structure and history.The significance to the public of our cultural heritage has motivated us to integrate outreach activity from the start, in particular a dynamic website using 4D data to allow an interactive tool for exploring the chosen case studies, reflecting the People at the Heart of ICT priority.The project includes industrial partners who will contribute resources and expertise in mid-IR lasers (Chromacity Ltd.) and mid-IR cameras (Thales Optronics Ltd.). Our partners have committed substantial in-kind support in the form of access to their technology and contributions of staff time. Furthermore, their engagement ensures that activities within the project, and the outcomes these generate, can be rapidly evaluated for adjacent commercial opportunities.EPSRC priorities are reflected in the project's structure. Cross-Disciplinarity is embedded as collaborations within the ICT community (Photonics & AI Technologies researchers) and with researchers from the AHRC-funded Cultural Heritage community. Co-Creation is essential: only by combining the distinct technical, contextual and material resources of each research group in our team will the project succeed in delivering new capabilities for IR imaging and analysis and new insights into culturally important objects of shared value.