Citation: |
|
[1] | Ronneberger O, Fischer P, Brox T. U-Net: convolutional networks for biomedical image segmentation[C]//Proceedings of the 18th International Conference on Medical Image Computing and Computer-Assisted Intervention, 2015. |
[2] | Zhou Z W, Siddiquee M R, Tajbakhsh N, et al. UNet++: a nested U-Net architecture for medical image segmentation[C]//Proceedings of the 4th International Workshop on Deep Learning in Medical Image Analysis, 2018. |
[3] | Huang G, Liu Z, van der Maaten L, et al. Densely connected convolutional networks[C]//Proceedings of 2017 IEEE Conference on Computer Vision and Pattern Recognition, 2017. |
[4] | Xiao X, Lian S, Luo Z M, et al. Weighted Res-UNet for high-quality retina vessel segmentation[C]//Proceedings of the 2018 9th International Conference on Information Technology in Medicine and Education, 2018. |
[5] | He K M, Zhang X Y, Ren S Q, et al. Deep residual learning for image recognition[C]//Proceedings of 2016 IEEE Conference on Computer Vision and Pattern Recognition, 2016. |
[6] | Chen L C, Zhu Y K, Papandreou G, et al. Encoder-decoder with atrous separable convolution for semantic image segmentation[C]//Proceedings of the 15th European Conference on Computer Vision, 2018. |
[7] | Badrinarayanan V, Kendall A, Cipolla R. SegNet: a deep convolutional encoder-decoder architecture for image segmentation[J]. IEEE Trans Pattern Anal Mach Intell, 2017, 39(12): 2481–2495. doi: 10.1109/TPAMI.2016.2644615 |
[8] | Zhang S C, Zhang Z, Sun L B, et al. One for all: a mutual enhancement method for object detection and semantic segmentation[J]. Appl Sci, 2020, 10(1): 13. |
[9] | Teichmann M, Weber M, Zöllner M, et al. MultiNet: real-time joint semantic reasoning for autonomous driving[C]//Proceedings of 2018 IEEE Intelligent Vehicles Symposium, 2018. |
[10] | Chen Z, Chen Z J. RBNet: a deep neural network for unified road and road boundary detection[C]//Proceedings of the 24th International Conference on Neural Information Processing, 2017. |
[11] | Oeljeklaus M, Hoffmann F, Bertram T. A fast multi-task CNN for spatial understanding of traffic scenes[C]//Proceedings of the 2018 21st International Conference on Intelligent Transportation Systems, 2018. |
[12] | Schlosser J, Chow C K, Kira Z. Fusing LIDAR and images for pedestrian detection using convolutional neural networks[C]//Proceedings of 2016 IEEE International Conference on Robotics and Automation, 2016. |
[13] | Caltagirone L, Bellone M, Svensson L, et al. LIDAR–camera fusion for road detection using fully convolutional neural networks[J]. Rob Auton Syst, 2019, 111: 125–131. doi: 10.1016/j.robot.2018.11.002 |
[14] | Chen Z, Zhang J, Tao D C. Progressive LiDAR adaptation for road detection[J]. IEEE/CAA J Automat Sin, 2019, 6(3): 693–702. doi: 10.1109/JAS.2019.1911459 |
[15] | van Gansbeke W, Neven D, de Brabandere B, et al. Sparse and noisy LiDAR completion with RGB guidance and uncertainty[C]//Proceedings of the 2019 16th International Conference on Machine Vision Applications, 2019. |
[16] | Wang T H, Hu H N, Lin C H, et al. 3D LiDAR and stereo fusion using stereo matching network with conditional cost volume normalization[C]//Proceedings of 2019 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2019. |
[17] | Zhang Y D, Funkhouser T. Deep depth completion of a single RGB-D image[C]//Proceedings of 2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2018. |
[18] | 邓广晖. 基于卷积神经网络的RGB-D图像物体检测和语义分割[D]. 北京: 北京工业大学, 2017. Deng G H. Object detection and semantic segmentation for RGB-D images with convolutional neural networks[D]. Beijing: Beijing University of Technology, 2017. |
[19] | 曹培. 面向自动驾驶的双传感器信息融合目标检测及姿态估计[D]. 哈尔滨: 哈尔滨工业大学, 2019. Cao P. Dual sensor information fusion for target detection and attitude estimation in autonomous driving[D]. Harbin: Harbin Institute of Technology, 2019. |
[20] | Fan R, Wang H L, Cai P D, et al. SNE-RoadSeg: incorporating surface normal information into semantic segmentation for accurate freespace detection[C]//Proceedings of the 16th European Conference on Computer Vision, 2020. |
[21] | Fan R, Wang H L, Xue B H, et al. Three-filters-to-normal: an accurate and ultrafast surface normal estimator[J]. IEEE Rob Automat Lett, 2021, 6(3): 5405–5412. doi: 10.1109/LRA.2021.3067308 |
Overview: Road detection is an important content of environmental identification in the field of automatic driving, and it is an important prerequisite for vehicles to realize automatic driving. Multi-source data fusion based on deep learning has become a hot topic in the field of automatic driving. RGB data can provide dense texture and color information, LiDAR data can provide accurate spatial information, and multi-sensor data fusion can improve the robustness and accuracy of detection. The latest fusion method uses convolutional neural network (CNN) as a fusion tool to fuse the LiDAR data and RGB image data, and semantic segmentation to realize road detection and segmentation. In this paper, different fusion methods of LiDAR point cloud and image data are adopted by encoder-decoder structure to realize road segmentation in traffic scenes. Aiming at the fusion methods of point cloud and image data, this paper proposes a variety of fusion schemes at pixel level, feature level, and decision level. In particular, four kinds of cross-fusion schemes are designed in feature level fusion. Various schemes are compared and studied to give the best fusion scheme. As for the network architecture, we use the encoder with residual network and the decoder with dense connection and jump connection as the basic network. The input image is RGB-D, and the LiDAR depth map is processed into a normal map by a surface normal estimator. The normal map features and RGB image features are fused at different levels of the network. The features are extracted through two input signals generated by two encoders, restored by a decoder, and finally road detection results are obtained by using sigmoid activation function. KITTI data set is used to verify the performances of various fusion schemes. The contrast experiments show that the proposed fusion scheme E can better learn the LiDAR point cloud information, the camera image information, the correlation of cross added point cloud, and image information. Also, it can reduce the loss of characteristic information, and thus has the best road segmentation effect. Through quantitative analysis of the average accuracy (AP) of different road detection methods, the optimal fusion method proposed in this paper shows the advantages of average detection accuracy, and has good overall performance. Through qualitative analysis of the performance of different detection methods in different scenarios, the results show that the fusion scheme E proposed in this paper has good detection results for the boundary area between vehicles and roads, and could effectively reduce the false detection rate of road detection.
Network infrastructure diagram
Decoder structure diagram
Surface normal estimator
Network structure with different fusion strategies
Cross fusion method.
Examples of experimental results of different fusion methods
Example of KITTI dataset experimental results