ADSCNet: asymmetric depthwise separable convolution for semantic segmentation in real-time

Semantic segmentation can be considered as a per-pixel localization and classification problem, which gives a meaningful label to each pixel in an input image. Deep convolutional neural networks have made extremely successful in semantic segmentation in recent years. However, some challenges still exist. The first challenge task is that most current networks are complex and it is hard to deploy these models on mobile devices because of the limitation of computational cost and memory. Getting more contextual information from downsampled feature maps is another challenging task. To this end, we propose an asymmetric depthwise separable convolution network (ADSCNet) which is a lightweight neural network for real-time semantic segmentation. To facilitating information propagation, Dense Dilated Convolution Connections (DDCC), which connects a set of dilated convolutional layers in a dense way, is introduced in the network. Pooling operation is inserted before ADSCNet unit to cover more contextual information in prediction. Extensive experimental results validate the superior performance of our proposed method compared with other network architectures. Our approach achieves mean intersection over union (mIOU) of 67.5% on Cityscapes dataset at 76.9 frames per second.