Synh Ha

Dr. Synh Ha

International University - Vietnam National University HCM City
orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

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

Representative Publications

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23 January 2018 in IEEE Transactions on Circuits and Systems for Video Technology
Verified
Journal Article
Closed access
TNTien Phuoc Nguyen
Tien Phuoc Nguyen
CPCuong Cao Pham
Cuong Cao Pham
Synh HaSynh Ha
Synh Ha
JJJae Wook Jeon
Jae Wook Jeon
Change/motion detection is a challenging problem in video analysis and surveillance system. Recently, the state-of-the-art methods using the sample-based background model have demonstrated astonishing results with this problem. However, they are ineffective in the dynamic scenes that contain complex motion patterns. In this paper, we introduce a novel data-driven approach that combines the sample-based background model with a feature extractor obtained by training a triplet network. We construct the network by three identical convolutional neural networks, each of which is called a motion feature network. Our network can automatically learn motion patterns from small image patches and transform input images of any size into feature embeddings for high-level representations. The sample-based background model of each pixel is then employed by using the color information and the extracted feature embeddings. We also propose an approach to generate triplet examples from CDNet 2014 for training our network model from scratch. The offline trained network can be used on the fly without re-training on any video sequence before each execution. Therefore, it is feasible for real-time surveillance systems. In this paper, we show that our method outperforms the other state-of-the-art methods on CDNet 2014 and other benchmarks (BMC and Wallflower).

1 January 2011
Verified
Book Chapter
Closed access
PDF file
CPCuong Cao Pham
Cuong Cao Pham
Synh HaSynh Ha
Synh Ha
JJJae Wook Jeon
Jae Wook Jeon

1 July 2017
Verified
Conference Paper
Closed access
Hung PhanHung Phan
Hung Phan
LPLong Hoang Pham
Long Hoang Pham
DTDuong Nguyen-Ngoc Tran
Duong Nguyen-Ngoc Tran
Synh HaSynh Ha
Synh Ha
Traffic Surveillance System (TSS) plays an important role in extracting necessary information (count, type, speed, etc.). In the area of Traffic Surveillance System (TSS), vehicle detection has emerged as an influential field of study. So far there has been a considerable amount of research to accommodate this subject. However, these studies almost address problems in developed countries where the traffic infrastructure is constructed to appropriate automobiles. Detecting moving vehicles in urban areas is difficult because the inter-vehicle space is significantly reduced, increasing the occlusion between vehicles. This issue is more challenging in developing countries where the roads are crowded with 2-wheeled motorbikes in rush hours. This paper presents a method to improve the occlusion vehicle detection from static surveillance cameras. The proposed method is a vision-based approach in which undefined blobs of occluded vehicles are examined to extract the vehicles individually based on the geometric and the ellipticity characteristic of objects' shapes. Experiments have been carried out with the real-world data to evaluate the performance and the accuracy of our method. The assessment results are promising for a detection rate of 84.10% at daytime.

14 August 2018 in IET Computer Vision
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Journal Article
Open access
PDF file
Synh HaSynh Ha
Synh Ha
DTDuong Nguyen-Ngoc Tran
Duong Nguyen-Ngoc Tran
TNTien Phuoc Nguyen
Tien Phuoc Nguyen
SDSon Vu‐Truong Dao
Son Vu‐Truong Dao
Background subtraction has been a fundamental task in video analytics and smart surveillance applications. In the field of background subtraction, Gaussian mixture model is a canonical model for many other methods. However, the unconscious learning of this model often leads to erroneous motion detection under high variation scenes. This article proposes a new method that incorporates entropy estimation and a removal framework into the Gaussian mixture model to improve the performance of background subtraction. Firstly, entropy information is computed for each pixel of a frame to classify frames into silent or high variation categories. Secondly, the removal framework is used to determine which frames from the background subtraction process are updated. The proposed method produces precise results with fast execution time, which are two critical factors in surveillance systems for more advanced tasks. The authors used two publicly available test sequences from the 2014 Change Detection and Scene background modelling data sets and internally collected data sets of scenes with dense traffic.

6 December 2020 in Sensors
Verified
Journal Article
Open access
PDF file
Synh HaSynh Ha
Synh Ha
Nhat ChungNhat Chung
Nhat Chung
Hung PhanHung Phan
Hung Phan
Cuong NguyenCuong Nguyen
Cuong Nguyen
Decades of ongoing research have shown that background modelling is a very powerful technique, which is used in intelligent surveillance systems, in order to extract features of interest, known as foregrounds. In order to work with the dynamic nature of different scenes, many techniques of background modelling adopted the unsupervised approach of Gaussian Mixture Model with an iterative paradigm. Although the technique has had much success, a problem occurs in cases of sudden scene changes with high variation (e.g., illumination changes, camera jittering) that the model unknowingly and unnecessarily takes into account those effects and distorts the results. Therefore, this paper proposes an unsupervised, parallelized, and tensor-based approach that algorithmically works with entropy estimations. These entropy estimations are used in order to assess the uncertainty level of a constructed background, which predicts both the present and future variations from the inputs, thereby opting to use either the incoming frames to update the background or simply discard them. Our experiments suggest that this method is highly integrable into a surveillance system that consists of other functions and can be competitive with state-of-the-art methods in terms of processing speed.

1 December 2013
Verified
Conference Paper
Closed access
LPLong Hoang Pham
Long Hoang Pham
TDTin Trung Duong
Tin Trung Duong
HTHa Manh Tran
Ha Manh Tran
Synh HaSynh Ha
Synh Ha
Vehicles detection and classification are the most popular subjects in the computer vision researching field, and also are the most important parts in any traffic monitoring or surveillance system. Although there has been a considerable amount of ideas to accommodate this problem since the 90s, many problems are still unresolved due to the complexity of traffic systems and the variety of vehicles. This paper is a work-in-process that proposes a new approach to detect and classify vehicles based on the traffic system in Vietnam. The main goal of this method is to group vehicles into 2 main classes, which are 2-wheeled and 4-wheeled vehicles, based on low-level traffic parameters in urban areas.