Gi Pyo Nam

Dr. Gi Pyo Nam

Center for Artificial Intelligence, Korea Institute of Science and Technology (KIST)
orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 June 2017 in Sensors
Verified
Journal Article
Open access
PDF file
KKKi Wan Kim
Ki Wan Kim
HGHong Hyung Gil
Hong Hyung Gil
GNGi Pyo Nam
Gi Pyo Nam
KPKang Ryoung Park
Kang Ryoung Park
The necessity for the classification of open and closed eyes is increasing in various fields, including analysis of eye fatigue in 3D TVs, analysis of the psychological states of test subjects, and eye status tracking-based driver drowsiness detection. Previous studies have used various methods to distinguish between open and closed eyes, such as classifiers based on the features obtained from image binarization, edge operators, or texture analysis. However, when it comes to eye images with different lighting conditions and resolutions, it can be difficult to find an optimal threshold for image binarization or optimal filters for edge and texture extraction. In order to address this issue, we propose a method to classify open and closed eye images with different conditions, acquired by a visible light camera, using a deep residual convolutional neural network. After conducting performance analysis on both self-collected and open databases, we have determined that the classification accuracy of the proposed method is superior to that of existing methods.

26 July 2019 in IEEE Transactions on Intelligent Transportation Systems
Verified
Journal Article
Closed access
ASArif Ahmed Sekh
Arif Ahmed Sekh
DDDebi Prosad Dogra
Debi Prosad Dogra
SKSamarjit Kar
Samarjit Kar
RPRenuka Patnaik
Renuka Patnaik
SLSeung-Cheol Lee
Seung-Cheol Lee
IKIg-Jae Kim
Ig-Jae Kim
Synopsis of a long-duration video has many applications in intelligent transportation systems. It can help to monitor traffic with lesser manpower. However, generating meaningful synopsis of a long-duration video recording can be challenging. Often summarized outputs include redundant contents or activities that may not be helpful to the observer. Moving object trajectories are possible sources of information that can be used to generate the synopsis of long-duration videos. The synopsis generation faces challenges due to object tracking, grouping of the trajectories with respect to activity type, object category, and contextual information, and generating smooth synopsis according to a query. In this paper, we propose a method to generate meaningful and smooth synopsis of long-duration videos according to the users' query. We have tracked moving objects and adopted deep learning to classify the objects into known categories (e.g., car, bike, and pedestrians). We then identify regions in the surveillance scene with the help of unsupervised clustering. Each tube (spatiotemporal object trajectory) is represented by the source and the destination. In the final stage, we take a query from the user and generate the synopsis video by smoothly blending the appropriate tubes over the background frame through energy minimization. The proposed method has been evaluated on two publicly available datasets and our own surveillance datasets. We have compared the method with popular state-of-the-art techniques. The experiments reveal that the proposed method is superior to the existing techniques and it produces visually seamless video synopsis.

23 November 2022 in IEEE Transactions on Intelligent Transportation Systems
Verified
Journal Article
Closed access
TVThakare Kamalakar Vijay
Thakare Kamalakar Vijay
DDDebi Prosad Dogra
Debi Prosad Dogra
HCHeeseung Choi
Heeseung Choi
GNGi Pyo Nam
Gi Pyo Nam
Ig-Jae KimIg-Jae Kim
Ig-Jae Kim
Road accidents are often caused by short abnormal events, including traffic violations, abrupt change in vehicular motion, driver fatigue, etc. Observing an accident event from the right camera perspective plays a crucial role while detecting accidents. However, it may not be possible to capture such abnormal events from a limited camera perspective. We present a deep learning framework to analyze the accident events recorded from multiple perspectives. First, we estimate feature similarity in videos recorded from multiple perspectives. We then divided the video samples into high and low feature similarity groups. Next, we extract spatio-temporal features from each group using two-branch DCNNs and fuse them using a rank-based weighted average pooling strategy followed by classification. We present a new road accident video dataset (MP-RAD), where each accident event is synthetically generated and captured from five independent camera perspectives using a computer gaming platform. Most of the existing road accident datasets use egocentric views or they are captured in fixed camera setups. However, our dataset is large and multi-perspective that can be used to validate ITS-related tasks such as accident detection, accident localization, traffic monitoring, etc. The dataset contains 400 accident events with a total of 2000 videos. We provide temporal annotations of all videos. The proposed framework and the dataset have been cross-validated with latest accident detection baselines trained on real-world road accident videos and vice-versa. The sub-optimal detection accuracy obtained using the baselines indicates that the proposed framework and the dataset can be useful for ITS related research. Code and dataset is available at: https://github.com/draxler1/MP-RAD-Dataset-ITS-

5 September 2018 in Applied Sciences
Verified
Journal Article
Open access
PDF file
GNGi Pyo Nam
Gi Pyo Nam
HCHeeseung Choi
Heeseung Choi
JCJunghyun Cho
Junghyun Cho
Ig-Jae KimIg-Jae Kim
Ig-Jae Kim
Face recognition is one research area that has benefited from the recent popularity of deep learning, namely the convolutional neural network (CNN) model. Nevertheless, the recognition performance is still compromised by the model’s dependency on the scale of input images and the limited number of feature maps in each layer of the network. To circumvent these issues, we propose PSI-CNN, a generic pyramid-based scale-invariant CNN architecture which additionally extracts untrained feature maps across multiple image resolutions, thereby allowing the network to learn scale-independent information and improving the recognition performance on low resolution images. Experimental results on the LFW dataset and our own CCTV database show PSI-CNN consistently outperforming the widely-adopted VGG face model in terms of face matching accuracy.

29 July 2020 in IEEE Access
Verified
Journal Article
Open access
THToan Minh Hoang
Toan Minh Hoang
GNGi Pyo Nam
Gi Pyo Nam
JCJunghyun Cho
Junghyun Cho
Ig-Jae KimIg-Jae Kim
Ig-Jae Kim
This study proposes a novel face detector called DEFace that focuses on the challenging tasks of face detection to cope with a small size that is under 12 pixels and occlusions due to a mask or human body parts. This study proposed the extended feature pyramid network (FPN) module to detect small faces by expanding the range of P layer, and the network by adding a receptive context module (RCM) after each predicted feature head from the top-down pathway in the FPN architecture to enhance the feature discriminability and the robustness. Based on the FPN principle, the combination between the low- and high-resolutions are beneficial for object detection with different object sizes. Furthermore, with assistance from the RCM, the proposed method can use a broad range of context information especially for small faces. To evaluate the performance of the proposed method, various public face datasets are used such as the WIDER Face dataset [1], the face detection dataset and benchmark (FDDB) [2], and the masked faces (MAFA) dataset [3], which consist of challenging samples such as small face regions and occlusions by hair or other people. The results indicate that DEFace can detect the face region more accurately in comparison to the other state-of-the-art methods while maintaining the processing time.

29 November 2017 in Symmetry
Verified
Journal Article
Open access
PDF file
YHYujin Hong
Yujin Hong
GNGi Pyo Nam
Gi Pyo Nam
HCHeeseung Choi
Heeseung Choi
JCJunghyun Cho
Junghyun Cho
Ig-Jae KimIg-Jae Kim
Ig-Jae Kim
In this paper, we present a novel framework for automatically assessing facial attractiveness that considers four ratio feature sets as objective elements of facial attractiveness. In our framework, these feature sets are combined with three regression-based predictors to estimate a facial beauty score. To enhance the system’s performance to make it comparable with human scoring, we apply a score fusion technique. Experimental results show that the attractiveness score obtained by the proposed framework better correlates with human assessments than the scores from other predictors. The framework’s modularity allows any features or predictors to be integrated into the facial attractiveness measure. Our proposed framework can be applied to many beauty-related fields, such as the plastic surgery, cosmetics, and entertainment industries.