CGLF-Net: Image Emotion Recognition Network by Combining Global Self-Attention Features and Local Multiscale Features

Convolutional neural networks (CNNs) are commonly employed for image emotion recognition owing to their ability to extract local features; however, they have difficulty capturing the global representations of images. In contrast, self-attention modules in a visual transformer network can capture long-range dependencies as global features. Some studies have shown that an image's local and global features determine the emotions of the image and that some local regions can generate an emotional prioritization effect. Therefore, we proposed combining global self-attention features and a local multiscale features network (CGLF-Net) to recognize an image's emotion, extracting image features from global and local perspectives. Specifically, the cross-scale transformer network is employed instead of convolution operations in the global feature branch to enhance its model feature representation. In the local feature branch, the improved feature pyramid module is applied to extract features from different sensory fields, thereby combining semantic information with different scales. Furthermore, the local attention module based on class activation maps guides the network to focus on locally salient regions. In addition, using multibranch loss functions, local and global feature branches are combined to enhance the ability to capture a comprehensive set of features. Consequently, the proposed network achieves recognition accuracies of 75.61% and 65.01% on the FI-8 benchmark dataset and Emotion-6 benchmark dataset, respectively. These results show that the proposed CGLF-Net reliably address the difficulty of extracting global features using CNNs, representing the classification performance of the state-of-the-art.