Bringing RGB and IR Together: Hierarchical Multi-Modal Enhancement for Robust Transmission Line Detection
Shengdong Zhang, Xiaoqin Zhang, Wenqi Ren, Linlin Shen, Shaohua Wan, Jun Zhang, Yujing M Jiang
TL;DR
This work tackles robust transmission line detection from multimodal RGB and IR imagery by introducing HMMEN, a hierarchical fusion framework that uses Mutual Multi-Modal Enhanced Blocks (MMEB) to mutually strengthen RGB and IR features and Feature Alignment Blocks (FAB) to align multi-scale feature maps via deformable convolutions. The approach addresses misalignment at both input and feature levels, leveraging lightweight MobileNet backbones for edge-friendly deployment. Through a designed loss combining Binary Cross-Entropy and Dice terms, and extensive ablations on a RGB–IR UAV dataset, HMMEN demonstrates superior boundary precision and reduced false positives under diverse weather and lighting. The results indicate strong potential for practical large-scale UAV inspections in rural power grids, delivering robust TL detection across challenging conditions.
Abstract
Ensuring a stable power supply in rural areas relies heavily on effective inspection of power equipment, particularly transmission lines (TLs). However, detecting TLs from aerial imagery can be challenging when dealing with misalignments between visible light (RGB) and infrared (IR) images, as well as mismatched high- and low-level features in convolutional networks. To address these limitations, we propose a novel Hierarchical Multi-Modal Enhancement Network (HMMEN) that integrates RGB and IR data for robust and accurate TL detection. Our method introduces two key components: (1) a Mutual Multi-Modal Enhanced Block (MMEB), which fuses and enhances hierarchical RGB and IR feature maps in a coarse-to-fine manner, and (2) a Feature Alignment Block (FAB) that corrects misalignments between decoder outputs and IR feature maps by leveraging deformable convolutions. We employ MobileNet-based encoders for both RGB and IR inputs to accommodate edge-computing constraints and reduce computational overhead. Experimental results on diverse weather and lighting conditionsfog, night, snow, and daytimedemonstrate the superiority and robustness of our approach compared to state-of-the-art methods, resulting in fewer false positives, enhanced boundary delineation, and better overall detection performance. This framework thus shows promise for practical large-scale power line inspections with unmanned aerial vehicles.
