  Focusing on the issue of how to effectively capture and utilize
cross-modality information in RGB-D salient object detection (SOD) task, we
present a convolutional neural network (CNN) model, named CIR-Net, based on the
novel cross-modality interaction and refinement. For the cross-modality
interaction, 1) a progressive attention guided integration unit is proposed to
sufficiently integrate RGB-D feature representations in the encoder stage, and
2) a convergence aggregation structure is proposed, which flows the RGB and
depth decoding features into the corresponding RGB-D decoding streams via an
importance gated fusion unit in the decoder stage. For the cross-modality
refinement, we insert a refinement middleware structure between the encoder and
the decoder, in which the RGB, depth, and RGB-D encoder features are further
refined by successively using a self-modality attention refinement unit and a
cross-modality weighting refinement unit. At last, with the gradually refined
features, we predict the saliency map in the decoder stage. Extensive
experiments on six popular RGB-D SOD benchmarks demonstrate that our network
outperforms the state-of-the-art saliency detectors both qualitatively and
quantitatively.
