Deep homography-based image stitching with enhanced small object detection

This study presents a novel image stitching methodology leveraging the backbone of YOLOv8 as a feature extractor, designed specifically to overcome limitations prevalent in traditional stitching techniques concerning small object detection and complex backgrounds. The proposed approach integrates a low-resolution feature map enhancement, a multi-scale feature extraction mechanism, and a deep homography estimation module. The low-resolution enhancement module utilizes an adaptive Squeeze-and-Excitation (SE) mechanism to significantly enhance the detection precision of small objects. Concurrently, the multi-scale feature extraction employs Spatial Pyramid Pooling to efficiently capture and fuse features across various resolutions, improving robustness and feature alignment in images characterized by complex textures and disparities. A core innovation of this research is the introduction of a deep learning-based homography estimation module, utilizing regression networks and Direct Linear Transformation (DLT) algorithms to compute accurate geometric transformations. Moreover, a specially designed weighted loss function emphasizes the alignment accuracy of small object regions during model training, thus reducing stitching artifacts and improving visual continuity. Experimental validation was conducted using the UDIS and MVS-Synth datasets. Results show significant improvements over baseline and comparative methods, achieving higher PSNR (26.36 and 26.42, respectively) and SSIM values (0.8414 and 0.8494, respectively), with substantial reductions in model size and computational complexity, as demonstrated by the model size (188 MB) and GFLOPs (14.5) in our experiments. Ablation studies further confirm the effectiveness of each module in enhancing stitching accuracy and computational efficiency. Future work may explore extending the model's capability for real-time application in dynamic and variable environments.