I was referring the following papers:
1. https://ethz.ch/content/dam/ethz/special-interest/baug/igp/p...
2. https://zpascal.net/cvpr2018/He_A_Twofold_Siamese_CVPR_2018_...
3. http://openaccess.thecvf.com/content_ECCV_2018/papers/Yunhua...