面向文化遗产数字孪生的热成像异常检测的按像素发射率校正（按材料分段）
Material-Segmented Per-Pixel Emissivity Correction for Thermographic Anomaly Detection in Cultural Heritage Digital Twins
AI总结：
该研究针对文化遗产热成像异常检测中发射率假设导致的伪影问题，提出基于SAM 3.1的无训练按像素发射率校正流程，经合成与真实数据集验证可降低温度反演误差，明确了校正的适用范围与失效模式。
AI中文摘要：
文化遗产表面的定量长波热成像受逆普朗克温度反演中全局恒定发射率假设的限制；在异质表面上，发射率在一个视场内发生变化，产生表观温度伪影，这些伪影会模拟并掩盖地下异常。我们提出了一种无需训练的流程，该流程通过将SAM 3.1开放词汇分割应用于共定位、共校准的RGB通道来推导按像素的发射率，将各分割区域映射到从基础测量文献汇编的材料键控长波红外（LWIR）发射率表，并将该场传播到对原始辐射数据的按像素逆普朗克求解中。由于缺乏包含原始辐射测量、温度参考和共定位RGB相机的公共数据集，我们基于基于物理的合成基准和四个真实数据集进行评估。在基准测试中，在涵盖低发射率例外情况的调色板下，该校正在20K对比度下将平均绝对误差从1.97K降至0.91K，且在发射率表准确时，在所有布局上都优于最佳拟合的全局恒定值；但在符合文化遗产实际情况的发射率分布下则不然。我们提供了量化的工作制度图，并提出了一项基于测量的发现，该发现修正了文化遗产领域的相关结论：风化的户外文化遗产发射率聚集在传统默认值附近，因此该校正在典型表面上的校正幅度较小，且集中在真正的低发射率例外情况上。我们还明确了主要失效模式，即开放词汇分割匹配的是外观而非材料，以及发射率定义的异常被抑制的禁忌制度。
英文摘要：
Quantitative longwave thermography of heritage surfaces is limited by the global-constant emissivity assumption in inverse-Planck temperature retrieval; on heterogeneous surfaces emissivity varies within one field of view, producing apparent-temperature artifacts that mimic and mask subsurface anomalies. We present a training-free pipeline that derives per-pixel emissivity by applying SAM 3.1 open-vocabulary segmentation to a colocated, co-calibrated RGB channel, mapping segments to a material-keyed LWIR emissivity table compiled from primary measurement literature, and propagating the field into a per-pixel inverse-Planck solve on raw radiometric data. Lacking any public dataset with raw radiometry, a temperature reference, and a colocated RGB camera, we evaluate on a physics-based synthetic benchmark and four real datasets. On the benchmark, under a palette spanning the low-emissivity exceptions, the correction cuts mean absolute error from 1.97 K to 0.91 K at 20 K contrast and, with an accurate table, beats the best fitted global constant on every layout; on a heritage-realistic emissivity distribution it does not. We contribute a quantified operating-regime map, and a measurement-backed finding that tempers the heritage claim: weathered outdoor heritage emissivities cluster near the conventional default, so the correction is small on typical surfaces and concentrated on genuine low-emissivity exceptions. We characterize the dominant failure mode, in which open-vocabulary segmentation matches appearance rather than material, and the contraindicated regime in which emissivity-defined anomalies are suppressed.
