P-MapNet: Far-seeing Map Generator Enhanced by both SDMap and HDMap Priors
Zhou Jiang, Zhenxin Zhu, Pengfei Li, Huan-ang Gao, Tianyuan Yuan, Yongliang Shi, Hang Zhao, Hao Zhao
TL;DR
The paper tackles the challenge of online HD map generation in regions lacking HDMap infrastructure by introducing P-MapNet, which jointly exploits SDMap priors from OpenStreetMap and an HDMap prior refined by a masked autoencoder. SDMap priors are fused into BEV features via multi-head cross-attention to mitigate misalignment, while the MAE-based HDMap prior refines the initial predictions to enforce realistic topology. On nuScenes and Argoverse2, P-MapNet yields substantial far-range gains, achieving up to 13.4% mIoU improvements at 240×60 m and up to 8.50 in vectorized AP, with HDMap priors improving perceptual realism by up to 6.34%; cross-dataset MAE pretraining indicates good generalization. The work demonstrates that combining weakly aligned SDMap skeletons with learned HDMap priors enables far-seeing HD map generation, offering practical benefits for online autonomous-driving perception and decision-making.
Abstract
Autonomous vehicles are gradually entering city roads today, with the help of high-definition maps (HDMaps). However, the reliance on HDMaps prevents autonomous vehicles from stepping into regions without this expensive digital infrastructure. This fact drives many researchers to study online HDMap generation algorithms, but the performance of these algorithms at far regions is still unsatisfying. We present P-MapNet, in which the letter P highlights the fact that we focus on incorporating map priors to improve model performance. Specifically, we exploit priors in both SDMap and HDMap. On one hand, we extract weakly aligned SDMap from OpenStreetMap, and encode it as an additional conditioning branch. Despite the misalignment challenge, our attention-based architecture adaptively attends to relevant SDMap skeletons and significantly improves performance. On the other hand, we exploit a masked autoencoder to capture the prior distribution of HDMap, which can serve as a refinement module to mitigate occlusions and artifacts. We benchmark on the nuScenes and Argoverse2 datasets. Through comprehensive experiments, we show that: (1) our SDMap prior can improve online map generation performance, using both rasterized (by up to $+18.73$ $\rm mIoU$) and vectorized (by up to $+8.50$ $\rm mAP$) output representations. (2) our HDMap prior can improve map perceptual metrics by up to $6.34\%$. (3) P-MapNet can be switched into different inference modes that covers different regions of the accuracy-efficiency trade-off landscape. (4) P-MapNet is a far-seeing solution that brings larger improvements on longer ranges. Codes and models are publicly available at https://jike5.github.io/P-MapNet.
