# ShuffleSeg: Real-time Semantic Segmentation Network

## TL;DR

ShuffleSeg is a computationally efficient real-time semantic segmentation network utilizing grouped convolution and channel shuffling, achieving a good balance of speed and accuracy suitable for mobile and robotics applications.

## Contribution

It introduces ShuffleSeg, a novel segmentation architecture optimized for real-time performance with significant FLOPs reduction and competitive accuracy.

## Key findings

- Achieves 2x GFLOPs reduction compared to previous methods.
- Maintains 58.3% mean IoU on CityScapes test set.
- Runs at 15.7 fps on NVIDIA Jetson TX2.

## Abstract

Real-time semantic segmentation is of significant importance for mobile and robotics related applications. We propose a computationally efficient segmentation network which we term as ShuffleSeg. The proposed architecture is based on grouped convolution and channel shuffling in its encoder for improving the performance. An ablation study of different decoding methods is compared including Skip architecture, UNet, and Dilation Frontend. Interesting insights on the speed and accuracy tradeoff is discussed. It is shown that skip architecture in the decoding method provides the best compromise for the goal of real-time performance, while it provides adequate accuracy by utilizing higher resolution feature maps for a more accurate segmentation. ShuffleSeg is evaluated on CityScapes and compared against the state of the art real-time segmentation networks. It achieves 2x GFLOPs reduction, while it provides on par mean intersection over union of 58.3% on CityScapes test set. ShuffleSeg runs at 15.7 frames per second on NVIDIA Jetson TX2, which makes it of great potential for real-time applications.