Fine-grained Object Categorization for Service Robots

A robot working in a human-centered environment is frequently confronted with fine-grained objects that must be distinguished from one another. Fine-grained visual classification (FGVC) still remains a challenging problem due to large intra-category dissimilarity and small inter-category dissimilarity. Furthermore, flaws such as the influence of illumination and information inadequacy persist in fine-grained RGB datasets. We propose a novel deep mixed multi-modality approach based on Vision Transformer (ViT) and Convolutional Neural Network (CNN) to improve the performance of FGVC. Furthermore, we generate two synthetic fine-grained RGB-D datasets consisting of 13 car objects with 720 views and 120 shoes with 7200 sample views. Finally, to assess the performance of the proposed approach, we conducted several experiments using fine-grained RGB-D datasets. Experimental results show that our method outperformed other baselines in terms of recognition accuracy, and achieved 93.40 $\%$ and 91.67 $\%$ recognition accuracy on shoe and car dataset respectively. We made the fine-grained RGB-D datasets publicly available for the benefit of research communities.