https://scholar.gist.ac.kr/handle/local/7911 Fri, 07 Aug 2026 05:16:58 GMT 2026-08-07T05:16:58Z https://scholar.gist.ac.kr/handle/local/19889 Title: Visual Multi-Object Tracking with Re-Identification using Labeled Random Finite Sets Author(s): MA, VAN LINH Abstract: 본 논문은 베이즈 필터링(Bayesian filtering)을 통해 객체 출현 및 재출현 그리고 가림 현상과 같은 문제를 해결하는 향상된 온라인 비주얼 다중 객체 추적(multi-object tracking)을 기법을 소개한다. 먼저, 객체의 사라짐 및 재출현 문제 해결을 위해, 라벨링 된 확률 유한 집합(labeled random finite set) 필터링 알고리즘을 제안한다. 이는 객체 관리를위해객체들의특징을활용하고,객체검출(detection)에대해선형시간복잡도로 작동하는새로운모델을포함한다.또한,궤적의겹침과크기를고려한퍼지(fuzzy)검출 모델이 가림 현상(occlusion) 처리를 개선하며, 계산 시간을 최소화하기 위해 근사화된 필터도함께제시된다.다음장에서는제안하는다중객체추적알고리즘을 2D이미지에 서실제 3D좌표로확장한다.이접근법은단안카메라의 2D검출들을통합함으로써 3D 다중 객체 추적을 향상시키고, 카메라 재구성 시 검출기 재학습의 필요성을 제거한다. 이를통해트랙초기화및종료,재식별,가림현상처리를단일베이즈필터링재귀로통 합하고, 나아가 객체의 특징, 운동 데이터, 기하학적 가림 모델을 활용하여 제안 기법의 효율성을 높인다. 마지막으로, 2D 바운딩 박스 검출만을 사용하여 실시간 다중 카메라 다중 객체 추적(multi-camera multi-object tracking)을 위한 빠른 온라인 알고리즘이 고 안된다. 이 방법은 다중 센서(multi-sensor) generalized labeled multi-Bernoulli 필터를 – iii – 낮은복잡도와정확도손실없이구현가능하게하고,동적카메라구성에대한강건함을 보여준다.|This dissertation introduces advanced methods for online visual multi-object track- ing (MOT), addressing challenges like object appearance-reappearance and occlusion, using Bayesian filtering techniques. We first introduce an algorithm that leverages la- beled random finite set (LRFS) filtering to tackle disappearance and reappearance issues, incorporating a novel model that utilizes object features to manage reappearing objects with linear complexity relative to the number of detections. A fuzzy detection model is also introduced to enhance occlusion handling by considering track overlaps and sizes. To reduce computational time, we propose an approximation of this filter. In the next chapter, we extend our proposed multi-object tracking algorithm from 2D images to 3D real-world coordinates. More specifically, this approach enhances 3D multi-object tracking by integrating 2D detections from monocular cameras, elim- inating the need for detector retraining upon camera reconfiguration. This solution combines track initiation/termination, re-identification, and occlusion handling into a single Bayes filtering recursion, with improved efficiency through feature and kinematic incorporation, and a geometric occlusion model. In the last chapter, a rapid online al- gorithm is presented for real-time multi-camera multi-object tracking, using only 2D bounding box detections. This method simplifies the Multi-Sensor Generalized La- beled Multi-Bernoulli (MS-GLMB) filter to achieve a low-complexity implementation, demonstrating faster performance without accuracy loss, and robustness to dynamic camera configurations. Tue, 31 Dec 2024 15:00:00 GMT https://scholar.gist.ac.kr/handle/local/19889 2024-12-31T15:00:00Z https://scholar.gist.ac.kr/handle/local/19883 Title: Vari-focal Light Field Camera for extended depth of field Author(s): Hyun Myung Kim Abstract: In recent years, as interest and demand for the metaverse and self-driving cars such as AR/VR have grown rapidly, great efforts have been made around the world to practicalize 3D depth sensing cameras. The light field camera, one of the three-dimensional depth-sensing cameras, is a camera that can detect depth with only one image sensor and is the most popular technology in practical aspects such as volume, cost, and battery consumption. Light field cameras can extract depth information from images such as those measured by multiple cameras, as microlens arrays act as key optical components for conventional cameras. In the existing light field camera, research on increasing the measurement range, angle of view, and depth resolution in the depth extraction area in the image processing area has been actively conducted. However, research in the hardware area of light field cameras was insufficient. Therefore, in this paper, we propose a study on the hardware implementation and characteristics of light field cameras. First, we propose an efficient processing method for microlens arrays, which are key components of light field cameras. Second, we devised a method of applying a variable-focus lens to widen the measurement distance of the light field camera. Third, we present a method for optimizing the light alignment of the microlens array to broaden the angle of view of the light field camera. Finally, we present a miniaturization method to apply light field cameras to mobile applications. Successful experimental demonstrations represent significant advances in the field of light field camera technology. Sat, 31 Dec 2022 15:00:00 GMT https://scholar.gist.ac.kr/handle/local/19883 2022-12-31T15:00:00Z https://scholar.gist.ac.kr/handle/local/33277 Title: Ultrasound Medical Imaging: A Novel Super-Resolution Imaging Technique Utilizing Random Interference Author(s): Pavel S. Ni Abstract: Medical imaging modalities are used every day in hospitals to examine medical condi-tions, consequently allowing us to analyze anatomical, physiological, metabolic, and functional information of the human body. Ultrasound is one of the most widely used diagnostic tools be-cause it is affordable and non-invasive. Ultrasound is used to assess the tissue, vessels, and or-gans within the human body. In the past few decades, a lot of effort was put by the academic community to improve the quality of ultrasound images. However, despite decades of innova-tion, the main disadvantage of ultrasound is low image resolution. In this dissertation, we develop a novel super-resolution imaging technique utilizing constructive and destructive interference of ultrasonic waves. In particular, we first introduce a method to generate an incident ultrasonic wavefront of random interference. This wavefront then has a spatially variant property that yields individual spatial points, in the region of interest, to reflect mutually incoherent spatial impulse responses. Second, we develop an image recon-struction method based on an L1-norm minimization algorithm that is capable of identifying the scattering points by the presence of spatial impulse responses in the received echo signals. The natural synergy between the properties of the wavefront of random interference and the image reconstruction algorithm allowed us to create the necessary conditions for a successful recon-struction of super-resolution ultrasound images. Lastly, we demonstrate using numerical simula-tions and phantom experiments that the proposed method can achieve four times better spatial resolution. In the simulation study, the proposed method achieved a resolution of 0.25 mm. In the real phantom experiment, we demonstrated that the proposed method can successfully re-construct ultrasound images of nylon wires as small as 0.08 mm in diameter using a tissue-mimicking phantom. We argue that the proposed method is a big step towards achieving super-resolution ultrasound imaging and offers a new perspective on ultrasound imaging. The pro-posed imaging method bypasses the diffraction resolution limit by eliminating the need for the conventional focused ultrasound beam. Thu, 31 Dec 2020 15:00:00 GMT https://scholar.gist.ac.kr/handle/local/33277 2020-12-31T15:00:00Z https://scholar.gist.ac.kr/handle/local/33278 Title: Ultra-thin films colorimetric sensors with highly absorbent media Author(s): Young Jin Yoo Abstract: Colorimetric sensing, which converts environmental changes into visible color changes, provides a simple yet powerful detection mechanism that is well-suited for the development of low-cost and low-power sensors. A new approach to colorimetric sensing uses the structural color of the photonic crystal to create color-changeable materials that are subject to environmental changes. Since a combination of introduced design methods for colorimetric detection, inspired by photonic structures, depends on highly ordered structures and periodically arranged refractive indices, concomitant co-assembling of multiple materials and micro/nano building blocks to achieve uniform colors at a large scale constrains their rapid and convenient fabrication. In this study, this thesis presents ultra-thin films colorimetric sensors with highly absorbent media. The ultra-thin films, as a simple structure, can be easily fabricated in various patterns with flexibility, even it is a powerful color-tunable structure. Recently, in our ongoing research, ultra-thin films exhibited colorimetric properties with sensitive color shifts in external refractive index change and subtle variations of coating thickness. With these properties, through the research process, optimal structures of ultra-thin films for each external environment changes will be designed and fabricated with flexible large-area samples. Thu, 31 Dec 2020 15:00:00 GMT https://scholar.gist.ac.kr/handle/local/33278 2020-12-31T15:00:00Z