Real-time Semantic Segmentation Comparative Study

The repository contains the official TensorFlow code used in our papers:

• RTSEG: REAL-TIME SEMANTIC SEGMENTATION COMPARATIVE STUDY for comparing different realtime semantic segmentation architectures.
• SHUFFLESEG: REAL-TIME SEMANTIC SEGMENTATION NETWORK which introduces a new fast realtime semantic segmentation network based on the ShuffleNet unit.

Description

Semantic segmentation benefits robotics related applications especially autonomous driving. Most of the research on semantic segmentation is only on increasing the accuracy of segmentation models with little attention to computationally efficient solutions. The few work conducted in this direction does not provide principled methods to evaluate the     different design choices for segmentation. In RTSeg, we address this gap by presenting a real-time semantic segmentation benchmarking framework with a decoupled design for feature extraction and decoding methods. The code and the experimental results are presented on the CityScapes dataset for urban scenes.

Models

Encoder	Skip	U-Net	DilationV1	DilationV2
VGG-16	Yes	Yes	Yes	No
ResNet-18	Yes	Yes	Yes	No
MobileNet	Yes	Yes	Yes	Yes
ShuffleNet	Yes	Yes	Yes	Yes

NOTE: The rest of the pretrained weights for all the implemented models will be released soon. Stay in touch for the updates.

Reported Results

Test Set

Model	GFLOPs	Class IoU	Class iIoU	Category IoU	Category iIoU
SegNet	286.03	56.1	34.2	79.8	66.4
ENet	3.83	58.3	24.4	80.4	64.0
DeepLab	-	70.4	42.6	86.4	67.7
SkipNet-VGG16	-	65.3	41.7	85.7	70.1
ShuffleSeg	2.0	58.3	32.4	80.2	62.2
SkipNet-MobileNet	6.2	61.5	35.2	82.0	63.0

Validation Set

Encoder	Decoder	Coarse	mIoU
MobileNet	SkipNet	No	61.3
ShuffleNet	SkipNet	No	55.5
ResNet-18	UNet	No	57.9
MobileNet	UNet	No	61.0
ShuffleNet	UNet	No	57.0
MobileNet	Dilation	No	57.8
ShuffleNet	Dilation	No	53.9
MobileNet	SkipNet	Yes	62.4
ShuffleNet	SkipNet	Yes	59.3

** GFLOPs is computed on image resolution 360x640. However, the mIOU(s) are computed on the official image resolution required by CityScapes evaluation script 1024x2048.**

Usage

1. Download the weights, processed data, and trained meta graphs from here
2. Extract pretrained_weights.zip
3. Extract full_cityscapes_res.zip under data/
4. Extract unet_resnet18.zip under experiments/

Run

The file named run.sh provide a good example for running different architectures. Have a look at this file.

Examples to the running command in run.sh file:

python3 main.py --load_config=[config_file_name].yaml [train/test] [Trainer Class Name] [Model Class Name]

• Remove comment from run.sh for running fcn8s_mobilenet on the validation set of cityscapes to get its mIoU. Our framework evaluation will produce results lower than the cityscapes evaluation script by small difference, for the final evaluation we use the cityscapes evaluation script. UNet ResNet18 should have 56% on validation set, but with cityscapes script we got 57.9%. The results on the test set for SkipNet-MobileNet and SkipNet-ShuffleNet are publicly available on the Cityscapes Benchmark.

python3 main.py --load_config=unet_resnet18_test.yaml test Train LinkNET

• To measure running time, run in inference mode.

python3 main.py --load_config=unet_resnet18_test.yaml inference Train LinkNET

• To run on different dataset or model, take one of the configuration files such as: config/experiments_config/unet_resnet18_test.yaml and modify it or create another .yaml configuration file depending on your needs.

NOTE: The current code does not contain the optimized code for measuring inference time, the final code will be released soon.

Main Dependencies

Python 3 and above
tensorflow 1.3.0/1.4.0
numpy 1.13.1
tqdm 4.15.0
matplotlib 2.0.2
pillow 4.2.1
PyYAML 3.12

All Dependencies

pip install -r [requirements_gpu.txt] or [requirements.txt]

Citation

If you find RTSeg useful in your research, please consider citing our work:

@ARTICLE{2018arXiv180302758S,
   author = {{Siam}, M. and {Gamal}, M. and {Abdel-Razek}, M. and {Yogamani}, S. and
    {Jagersand}, M.},
    title = "{RTSeg: Real-time Semantic Segmentation Comparative Study}",
  journal = {ArXiv e-prints},
archivePrefix = "arXiv",
   eprint = {1803.02758},
 primaryClass = "cs.CV",
 keywords = {Computer Science - Computer Vision and Pattern Recognition},
     year = 2018,
    month = mar,
   adsurl = {http://adsabs.harvard.edu/abs/2018arXiv180302758S},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

If you find ShuffleSeg useful in your research, please consider citing it as well:

@ARTICLE{2018arXiv180303816G,
   author = {{Gamal}, M. and {Siam}, M. and {Abdel-Razek}, M.},
    title = "{ShuffleSeg: Real-time Semantic Segmentation Network}",
  journal = {ArXiv e-prints},
archivePrefix = "arXiv",
   eprint = {1803.03816},
 primaryClass = "cs.CV",
 keywords = {Computer Science - Computer Vision and Pattern Recognition},
     year = 2018,
    month = mar,
   adsurl = {http://adsabs.harvard.edu/abs/2018arXiv180303816G},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.