一种基于面向对象策略的增强型光学遥感影像时空融合方法

An Enhanced Spatiotemporal Fusion Method for Optical Remote Sensing Imagery Based on Object-Oriented Strategy

  • 摘要: 时空融合技术能够利用多源光学影像时空信息的互补性重建高时空分辨率影像,兼具低成本和灵活的优势,其中近年提出的鲁棒自适应时空融合方法(reliable and adaptive spatiotemporal data fusion method, RASDF)因面对异源影像差异时鲁棒性表现优秀,能够重建剧烈变化场景下的地表信息而受到关注,但该方法存在效率低下和融合结果边界信息模糊的问题。对此,提出一种基于面向对象策略的增强型RASDF(object level RASDF, OL-RASDF)。该方法通过引入多尺度影像分割技术,基于分割块内像元时空变化模式相同等假设,将原方法中基于滑动窗口策略的加权结合邻域信息的像元级融合步骤转换为以分割块为基本处理单元的对象级融合步骤,从而使融合步骤更加轻量,并增强方法对地物边界信息的保留能力。两个地区的实验结果表明,OL-RASDF取得了最佳的融合精度,融合结果的边界信息最清晰,且融合效率优势显著,在两个实验区融合时间平均减少62.1%,表明OL-RASDF在长时序、大面积影像融合任务中具有更强的适用性。

     

    Abstract:
    Objectives Spatiotemporal fusion technology generates high spatiotemporal resolution images by leveraging the complementary spatiotemporal information of multisource optical images, offering cost-effective and flexible solutions, garnering widespread attention. Among these methods, the reliable and adaptive spatiotemporal data fusion method (RASDF) is recognized for its robustness in handling discrepancies between heterogeneous images and its ability to reconstruct surface information under drastic change scenarios. However, RASDF is hindered by inefficiencies and blurred boundary information in fusion results. To address these limitations, this study introduces an enhanced RASDF method based on an object-oriented strategy, termed object level RASDF (OL-RASDF).
    Methods By incorporating multi-scale imagesegmentation techniques and assuming consistent spatiotemporal variation patterns within segmented objects, OL-RASDF replaces the original pixel-level fusion steps, which rely on a moving window strategy, with object-level fusion steps that use image segments as the basic processing units. This approach streamlines the fusion process and enhances the preservation of boundary information.
    Results Experimental results from two study areas demonstrate that OL-RASDF achieves the highest fusion accuracy, the sharpest boundary details, and a significant improvement in efficiency. The average processing time in the two study areas was reduced by 62.1%.
    Conclusions The results indicate that OL-RASDF is highly applicable to long-term and large-scale image fusion tasks, offering a superior balance of accuracy and efficiency.

     

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