  Benefit from the quick development of deep learning techniques, salient
object detection has achieved remarkable progresses recently. However, there
still exists following two major challenges that hinder its application in
embedded devices, low resolution output and heavy model weight. To this end,
this paper presents an accurate yet compact deep network for efficient salient
object detection. More specifically, given a coarse saliency prediction in the
deepest layer, we first employ residual learning to learn side-output residual
features for saliency refinement, which can be achieved with very limited
convolutional parameters while keep accuracy. Secondly, we further propose
reverse attention to guide such side-output residual learning in a top-down
manner. By erasing the current predicted salient regions from side-output
features, the network can eventually explore the missing object parts and
details which results in high resolution and accuracy. Experiments on six
benchmark datasets demonstrate that the proposed approach compares favorably
against state-of-the-art methods, and with advantages in terms of simplicity,
efficiency (45 FPS) and model size (81 MB).
