Depth Injection Framework for RGBD Salient Object Detection.

Depth data with a predominance of discriminative power in location is advantageous for accurate salient object detection (SOD). Existing RGBD SOD methods have focused on how to properly use depth information for complementary fusion with RGB data, having achieved great success. In this work, we attempt a far more ambitious use of the depth information by injecting the depth maps into the encoder in a single-stream model. Specifically, we propose a depth injection framework (DIF) equipped with an Injection Scheme (IS) and a Depth Injection Module (DIM). The proposed IS enhances the semantic representation of the RGB features in the encoder by directly injecting depth maps into the high-level encoder blocks, while helping our model maintain computational convenience. Our proposed DIM acts as a bridge between the depth maps and the hierarchical RGB features of the encoder and helps the information of two modalities complement and guide each other, contributing to a great fusion effect. Experimental results demonstrate that our proposed method can achieve state-of-the-art performance on six RGBD datasets. Moreover, our method can achieve excellent performance on RGBT SOD and our DIM can be easily applied to single-stream SOD models and the transformer architecture, proving a powerful generalization ability.