Local feature extraction method based on feature aggregation, mixed convolution and attention
摘要
Local feature extraction, as the core component of feature matching, directly determines matching accuracy. To address the weak representational ability in low-texture regions, the lack of long-range dependencies, and the loss of structural details in local features, this paper proposes a local feature extraction method based on feature aggregation, mixed convolution and attention mechanisms, built upon the accelerated feature extraction network. First, a feature aggregation module is introduced in the feature extraction stage to enhance the representation of local features in low-texture regions. A local detail estimation branch and an efficient approximate attention branch collaboratively capture local detail information and non-local structural information, respectively. Second, to address the lack of long-range dependencies in local features, a mixed convolution–attention module is introduced in the feature fusion stage. Through the parallel extraction of the convolutional branch and the self-attention branch, the module enables local detail capture and global dependency modeling. Finally, a dynamic sampling strategy is adopted in the upsampling stage to alleviate structural detail loss caused by fixed bilinear interpolation. By adaptively adjusting the sampling positions, cross-scale feature alignment and accurate reconstruction of structural details are achieved. Experimental results demonstrate that, on the MegaDepth dataset, the proposed method achieves AUC@5°, AUC@10°, and AUC@20° of 46.4%, 59.6%, and 70.7%, representing improvements of 6.4%, 5.1%, and 4.3% over XFeat in the downstream camera pose estimation task.