New website getting online, testing
    • 摘要: 随着点云数据在虚拟现实、计算机视觉、机器人等领域中的广泛应用,点云获取与处理中的失真评价正成为一个重要的研究问题。考虑到点云三维信息对几何失真敏感、点云二维投影图包含丰富的纹理和语义信息,提出一种基于三维与二维特征融合的无参考点云质量评价方法,以有效结合点云的三维与二维特征信息,提高点云质量评价的准确性。对于三维特征提取,先对点云进行最远点采样,以选取的点为中心生成互不重叠的点云子模型,尽可能地覆盖整个点云模型,利用多尺度三维特征提取网络提取体素和点的特征。对于二维特征提取,先对点云进行正交6面投影,再通过多尺度二维特征提取网络提取纹理和语义信息。最后,考虑到人类视觉系统处理不同类型信息时会存在分割处理和交织融合的过程,设计一个对称跨模态注意模块融合三维和二维特征。在5个公开点云质量评价数据库上的实验结果显示,所提方法的皮尔逊线性相关系数(Pearson’s linear correlation coefficient,PLCC)分别达到0.92030.94630.9125、0.916和0.921,表明与现有的代表性点云质量评价方法相比,所提方法更优。

       

      Abstract: With the wide application of point clouds in virtual reality, computer vision, robotics and other fields, the assessment of distortions resulted from point cloud acquisition and processing is becoming an important research topic. Considering that the three-dimensional information of point clouds is sensitive to geometric distortion and the two-dimensional projection of point clouds contains rich texture and semantic information, a no-reference point cloud quality assessment method based on the fusion of three-dimensional and two-dimensional features is proposed to effectively combine the three-dimensional and two-dimensional feature information of point cloud and improve the accuracy of point cloud quality assessment. For 3D feature extraction, the farthest point sampling is firstly implemented on the point cloud, and then the non-overlapping point cloud sub-models centered on the selected points are generated, to cover the whole point cloud model as much as possible and use a multi-scale 3D feature extraction network to extract the features of voxels and points. For 2D feature extraction, the point cloud is first projected with orthogonal hexahedron projection, and then the texture and semantic information are extracted by a multi-scale 2D feature extraction network. Finally, considering the process of segmentation and interweaving fusion that occurs when the human visual system processes different types of information, a symmetric cross-modal attention module is designed to integrate 3D and 2D features. The experimental results on five public point cloud quality assessment datasets show that the Pearson’s linear correlation coefficient (PLCC) of the proposed method reaches 0.9203, 0.9463, 0.9125, 0.9164 and 0.9209 respectively, indicating that the proposed method has advanced performance compared with the existing representative point cloud quality assessment methods.