LFFNet: lightweight feature-enhanced fusion network for real-time semantic segmentation of road scenes

Deep neural networks have significantly improved semantic segmentation, but their great performance frequently comes at the expense of expensive computation and protracted inference times, which fall short of the exacting standards of real-world applications. A lightweight feature-enhanced fusion network (LFFNet) for real-time semantic segmentation is proposed. LFFNet is a particular type of asymmetric encoder–decoder structure. In the encoder, A multi-dilation rate fusion module can guarantee the retention of local information while enlarging the appropriate field in the encoder section, which resolves the issue of insufficient feature extraction caused by the variability of target size. In the decoder, different decoding modules are designed for spatial information and semantic information. The attentional feature enhancement module takes advantage of the attention mechanism to feature-optimize the contextual information of the high-level output, and the lightweight multi-scale feature fusion module fuses the features from various stages to aggregate more spatial detail information and contextual semantic information. The experimental findings demonstrate that LFFNet achieves 72.1% mIoU and 67.0% mIoU on Cityscapes and Camvid datasets at 102 FPS and 244 FPS, respectively, with only 0.63M parameters. Note that there is neither pretraining nor pre-processing. Our model can achieve superior segmentation performance with fewer parameters and less computation compared to existing networks.