Semantic segmentation for large-scale point clouds based on hybrid attention and dynamic fusion

This paper investigates the semantic segmentation problem for large-scale point clouds. Recent segmentation methods usually employ an encoder-decoder architecture. However, these methods may not effectively extract neighboring information in the encoder. Additionally, they typically use nearest neighbor interpolation and skip connections in the decoder, overlooking the semantic gap between encoder and decoder features. To resolve these issues, we propose HADF-Net, which consists of a Hybrid Attention Encoder (HAE), an Edge Dynamic Fusion module (EDF), and a Dynamic Cross-attention Decoder (DCD). HAE leverages the distinctive properties of geometric and semantic relations to aggregate local features at different stages. EDF aims to alleviate information loss during decoder upsampling by dynamically integrating the neighboring information. DCD employs an enhanced fusion mechanism with spatial-wise cross-attention to bridge the semantic gap between encoder and decoder features. Experimental results on 4 datasets demonstrate that our HADF-Net achieves superior performance.