Single-Stage Instance Shadow Detection with Bidirectional Relation Learning (CVPR 2021 Oral)

Tianyu Wang*, Xiaowei Hu*, Chi-Wing Fu, and Pheng-Ann Heng (* Joint first authors.)

Instance Shadow Detection aims to find shadow instances, object instances and shadow-object associations; this task benefits many vision applications, such as light direction estimation and photo editing.

In this paper, we present a new single-stage fully convolutional network architecture with a bidirectional relation learning module to directly learn the relations of shadow and object instances in an end-to-end manner.

[📄 Paper] [👇🏼 Video]

Requirement

pip install -r requirement.txt

Note that we tested on CUDA10.2 / PyTorch 1.6.0, CUDA11.1 / PyTorch 1.8.0 and Colab.

Installation

This repo is implemented on AdelaiDet, so first build it with:

$ cd SSIS
$ python setup.py build develop

Dataset and pre-trained model

Download the dataset and model_final.pth from Google drive. Put dataset file in the ../dataset/ and put pretrained model in the tools/output/SSIS_MS_R_101_bifpn_with_offset_class/. Note that we add new annotation file in the SOBA dataset.

Quick Start

Demo

To evaluate the results, try the command example:

$ cd demo
$ python demo.py --input ./samples

Training

$ cd tools
$ python train_net.py \
    --config-file ../configs/SSIS/MS_R_101_BiFPN_with_offset_class.yaml \
    --num-gpus 2 

Evaluation

$ python train_net.py \
    --config-file ../configs/SSIS/MS_R_101_BiFPN_with_offset_class.yaml \
    --num-gpus 2 --resume --eval-only
$ python SOAP.py --path PATH_TO_YOUR_DATASET/SOBA \ 
    --input-name ./output/SSIS_MS_R_101_bifpn_with_offset_class

Citation

If you use LISA, SSIS, SOBA, or SOAP, please use the following BibTeX entry.

@InProceedings{Wang_2020_CVPR,
author    = {Wang, Tianyu and Hu, Xiaowei and Wang, Qiong and Heng, Pheng-Ann and Fu, Chi-Wing},
title     = {Instance Shadow Detection},
booktitle = {IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)},
month     = {June},
year      = {2020}
}

@InProceedings{Wang_2021_CVPR,
author    = {Wang, Tianyu and Hu, Xiaowei and Fu, Chi-Wing and Heng, Pheng-Ann},
title     = {Single-Stage Instance Shadow Detection With Bidirectional Relation Learning},
booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)},
month     = {June},
Year      = {2021},
pages     = {1-11}
}