Saliency Hierarchy Modeling via Generative Kernels for Salient Object Detection

Salient Object Detection (SOD) is a challenging problem that aims to precisely recognize and segment the salient objects. In ground-truth maps, all pixels belonging to the salient objects are positively annotated with the same value. However, the saliency level should be a relative quantity, which varies among different regions in a given sample and different samples. The conflict between various saliency levels and single saliency value in ground-truth, results in learning difficulty. To alleviate the problem, we propose a Saliency Hierarchy Network (SHNet), modeling saliency patterns via generative kernels from two perspectives: region-level and sample-level. Specifically, we construct a Saliency Hierarchy Module to explicitly model saliency levels of different regions in a given sample with the guide of prior knowledge. Moreover, considering the sample-level divergence, we introduce a Hyper Kernel Generator to capture the global contexts and adaptively generate convolution kernels for various inputs. As a result, extensive experiments on five standard benchmarks demonstrate our SHNet outperforms other state-of-the-art methods in both terms of performance and efficiency.