To address 3D object retrieval, substantial efforts have been made to
generate highly discriminative descriptors of 3D objects represented by a
single modality, e.g., voxels, point clouds or multi-view images. It is
promising to leverage the complementary information from multi-modality
representations of 3D objects to further improve retrieval performance.
However, multi-modality 3D object retrieval is rarely developed and analyzed on
large-scale datasets. In this paper, we propose self-and-cross attention based
aggregation of point cloud and multi-view images (SCA-PVNet) for 3D object
retrieval. With deep features extracted from point clouds and multi-view
images, we design two types of feature aggregation modules, namely the
In-Modality Aggregation Module (IMAM) and the Cross-Modality Aggregation Module
(CMAM), for effective feature fusion. IMAM leverages a self-attention mechanism
to aggregate multi-view features while CMAM exploits a cross-attention
mechanism to interact point cloud features with multi-view features. The final
descriptor of a 3D object for object retrieval can be obtained via
concatenating the aggregated features from both modules. Extensive experiments
and analysis are conducted on three datasets, ranging from small to large
scale, to show the superiority of the proposed SCA-PVNet over the
state-of-the-art methods.

我们提出了基于点云和多视角图像的自我和交叉注意力聚合方法 (SCA-PVNet) 来进行三维目标检索，通过设计两种特征聚合模块（即 In-Modality Aggregation Module (IMAM) 和 Cross-Modality Aggregation Module (CMAM)），通过自我和交叉注意力机制有效地融合多视角特征和点云特征，从而获得目标检索的最终描述符。我们在从小到大范围的三个数据集上进行了大量实验和分析，证明了提出的 SCA-PVNet 方法在三维目标检索领域的卓越性能。