Mask prior generation with language queries guided networks for referring image segmentation

The aim of Referring Image Segmentation (RIS) is to generate a pixel-level mask to accurately segment the target object according to its natural language expression. Previous RIS methods ignore exploring the significant language information in both the encoder and decoder stages, and simply use an upsampling-convolution operation to obtain the prediction mask, resulting in inaccurate visual object locating. Thus, this paper proposes a Mask Prior Generation with Language Queries Guided Network (MPG-LQGNet). In the encoder of MPGLQGNet, a Bidirectional Spatial Alignment Module (BSAM) is designed to realize the bidirectional fusion for both vision and language embeddings, generating additional language queries to understand both the locating of targets and the semantics of the language. Moreover, a Channel Attention Fusion Gate (CAFG) is designed to enhance the exploration of the significance of the cross-modal embeddings. In the decoder of the MPG-LQGNet, the Language Query Guided Mask Prior Generator (LQPG) is designed to utilize the generated language queries to activate significant information in the upsampled decoding features, obtaining the more accurate mask prior that guides the final prediction. Extensive experiments on RefCOCO series datasets show that our method consistently improves over state-of-the-art methods. The source code of our MPG-LQGNet is available at https://github.com/SWU-CS-MediaLab/MPG-LQGNet.