Acquisition Geometry-Assisted Whole-Group Localization of X-ray Fluorescence Maps in Optical Microscopy Images

基于采集几何辅助的光学显微图像中 X 射线荧光图的整体组定位

Abstract: X-ray fluorescence (XRF) microscopy maps elemental distributions, while optical microscopy can provide complementary morphological context. Localizing XRF fields of view (FOVs) in optical images is difficult because the two modalities differ in contrast mechanism and resolution. Most current workflows place each XRF tile independently, even when acquisition metadata already record the tiles’ relative scan positions.

摘要： X 射线荧光（XRF）显微镜用于绘制元素分布图，而光学显微镜则能提供互补的形态学背景。由于两种成像模式在对比度机制和分辨率上存在差异，在光学图像中定位 XRF 视场（FOV）具有一定难度。目前大多数工作流程在处理时，即使采集元数据中已经记录了各图块（tile）的相对扫描位置，仍倾向于将每个 XRF 图块独立进行定位。

This study formalizes XRF tile-group localization, in which one optical-frame placement is estimated for the whole group, constrained by acquisition geometry and quantified using group intersection-over-union (GroupIoU). In a controlled case study, independent localization failed with GroupIoU 0.000, whereas group localization achieved 0.931. Replacing the normalized cross-correlation (NCC) metric with mutual information (MI) gave nearly identical results, showing that the outcome is not specific to one local similarity metric.

本研究将 XRF 图块组定位形式化，即通过采集几何约束，为整个图块组估算一个光学框架位置，并使用组交并比（GroupIoU）进行量化。在一项对照案例研究中，独立定位方法的 GroupIoU 为 0.000（失败），而组定位方法达到了 0.931。将归一化互相关（NCC）指标替换为互信息（MI）后，结果几乎一致，这表明该结果并不依赖于特定的局部相似性度量指标。

In another multiscale case study, using a coarse XRF survey scan to connect the fine-scale tile group to the optical image increased mean GroupIoU from 0.694 to 0.856. These case studies support using acquisition geometry as an explicit constraint when localizing related XRF tiles.

在另一个多尺度案例研究中，利用粗略的 XRF 概览扫描将精细尺度的图块组与光学图像进行关联，使平均 GroupIoU 从 0.694 提高到了 0.856。这些案例研究支持在定位相关 XRF 图块时，将采集几何作为一种显式约束条件。