空间尺度变化驱动的光学遥感特征流形几何演化建模

Modeling the Geometric Evolution of Optical Remote Sensing Feature Manifolds Driven by Spatial Scale Variation

  • 摘要: 针对光学遥感影像多空间尺度中离散建模难以刻画特征流形连续演化规律的问题,提出基于条件流匹配(CFM)的多尺度特征流形几何演化建模方法。以ConvNeXt-Tiny为基础模型分别提取浅层与深层特征,经Procrustes对齐后用CFM学习尺度驱动的连续速度场,构建内在维度、微分熵、互信息等5维指标体系。实验采用NWPU-RESISC45数据集在1至4倍降采样下验证,实验结果表明,特征流形演化呈现以下三项主要规律:一是维度坍缩,深层内在维度下降61.3%准确率仅降5.5%,坍缩主要消除冗余维度;二是信息非单调保持,浅层互信息于1.5倍处峰值增幅11.4%,适度降采样表现出正则化效应;三是聚类分离度提升,深层轮廓系数提升150%、类间-类内距离比提升135%。消融实验证实了连续速度场拟合依赖对齐与语义约束协同作用。此方法为遥感特征多尺度演化研究提供了连续建模视角与定量依据。

     

    Abstract: Objectives: Optical remote sensing imagery spans a wide range of spatial scales, and the geometric structure of deep features evolves continuously with resolution. However, existing discrete modeling samples only a finite set of isolated scales and therefore cannot capture the continuous evolution of feature manifolds across scales. To address this limitation, this study aims to establish a continuous, geometry-aware characterization of multi-scale feature manifold evolution, to quantify how scale transformations reshape the intrinsic structure of shallow and deep representations, and to provide a quantitative basis for scale-robust remote sensing interpretation. Methods: This study proposes a Conditional Flow Matching (CFM)-based method for modeling the geometric evolution of multi-scale feature manifolds. ConvNeXt-Tiny serves as the base model, from which shallow and deep features are extracted separately. Because features at different depths occupy heterogeneous representation spaces, Procrustes analysis aligns them in a unified geometric space and establishes reliable cross-scale correspondence. On this basis, CFM learns a scale-driven continuous velocity field that smoothly transports the feature manifold along the scale axis, enabling the characterization of geometric states at arbitrary intermediate scales. For quantitative evaluation, a five-dimensional metric system is constructed, comprising intrinsic dimension, differential entropy, mutual information, silhouette coefficient, and the inter-class to intra-class distance ratio. Experiments are conducted on the NWPU-RESISC45 dataset at down-sampling rates from 1× to 4×, with classification accuracy as a task-level reference. Results: The experiments reveal three principal patterns in feature manifold evolution. First, dimension collapse occurs in deep features: the intrinsic dimension decreases by 61.3%, whereas classification accuracy drops by only 5.5%, indicating that collapse primarily eliminates redundant dimensions and that the compact semantic subspace remains intact. Second, information preservation is non-monotonic: the mutual information of shallow features peaks at the 1.5× scale, an increase of 11.4%, demonstrating the regularization effect of moderate down-sampling. Third, cluster separability improves: the silhouette coefficient of deep features increases by 150%, and the inter-class to intra-class distance ratio increases by 135%. Ablation experiments confirm that this improvement depends on the synergy of Procrustes alignment and semantic constraints. Conclusions: The proposed method replaces discrete scale sampling with continuous geometric modeling and demonstrates that multi-scale feature evolution is a structured process of redundancy elimination, information regularization, and separability enhancement rather than monotonic degradation. These findings provide a continuous modeling perspective and a quantitative basis for multi-scale feature evolution research in remote sensing. They also offer practical guidance for scale selection, multi-scale feature fusion, and resolution-robust model design.

     

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