Salient object detection for RGB-D images by generative adversarial network

Salient object detection for RGB-D image aims to automatically detect the objects of human interest by color and depth information. In the paper generative adversarial network is adopted to improve its performance by adversarial learning. Generator network takes RGB-D images as inputs and outputs synthetic saliency maps. It adopts double stream network to extract color and depth feature individually and then fuses them from deep to shallow progressively. Discriminator network takes RGB image and synthetic saliency maps (RGBS), RGB image and ground truth saliency map (RGBY) as inputs, and outputs their labels indicating whether input is synthetics or ground truth. It consists of three convolution blocks and three fully connected layers. In order to pursuit long-range dependency of feature, self-attention layer is inserted in both generator and discriminator network. Supervised by real labels and ground truth saliency map, discriminator network and generator network are adversarial trained to make generator network cheat discriminator network successfully and discriminator network distinguish synthetics or ground truth correctly. Experiments demonstrate adversarial learning enhances the ability of generator network, RGBS and RGBY input in discriminator network and self-attention layer play an important role in improving the performance. Meanwhile our method outperforms state-of-the-art methods.