MoE-SPNet: A Mixture-of-Experts Scene Parsing Network

TL;DR

This paper introduces MoE-SPNet, a novel scene parsing network that uses a mixture-of-experts approach to adaptively weight multi-scale features spatially, improving scene understanding accuracy.

Contribution

It proposes a mixture-of-experts layer and an adaptive hierarchical feature aggregation mechanism for better multi-scale feature utilization in scene parsing.

Findings

Improved accuracy on PASCAL VOC 2012 dataset.

Enhanced performance on SceneParse150 dataset.

Effective feature weighting improves scene parsing results.

Abstract

Scene parsing is an indispensable component in understanding the semantics within a scene. Traditional methods rely on handcrafted local features and probabilistic graphical models to incorporate local and global cues. Recently, methods based on fully convolutional neural networks have achieved new records on scene parsing. An important strategy common to these methods is the aggregation of hierarchical features yielded by a deep convolutional neural network. However, typical algorithms usually aggregate hierarchical convolutional features via concatenation or linear combination, which cannot sufficiently exploit the diversities of contextual information in multi-scale features and the spatial inhomogeneity of a scene. In this paper, we propose a mixture-of-experts scene parsing network (MoE-SPNet) that incorporates a convolutional mixture-of-experts layer to assess the importance of features from different levels and at different spatial locations. In addition, we propose a variant of mixture-of-experts called the adaptive hierarchical feature aggregation (AHFA) mechanism which can be incorporated into existing scene parsing networks that use skip-connections to fuse features layer-wisely. In the proposed networks, different levels of features at each spatial location are adaptively re-weighted according to the local structure and surrounding contextual information before aggregation. We demonstrate the effectiveness of the proposed methods on two scene parsing datasets including PASCAL VOC 2012 and SceneParse150 based on two kinds of baseline models FCN-8s and DeepLab-ASPP.