Research/Working Experience and Projects
Prediction of Perceptible Artifacts in JPEG 2000 Compression of CT Images using Image Quality Metrics
Assessment of Visually Lossless Threshold for Irreversible JPEG 2000 Compression of CT Images
Visualization of Concordance of Sets
Development of PACS Software, Infinitt G3
Extension of Rapidia 3D for Semiautomatic Segmentation of MRI images; Collaboration with Children's National Medical Center, USA
Development of Option Functions for Rapidia 3D
Development of Commercial 3D Imaging Software, Rapidia 3D
Development of 3D Computerized Human Anatomic Atlas and Medical Imaging Library
Image Database Construction for Medical Diagnosis Assistance
Binary Volume Rendering Using the Visible Human Data
Development of Hyper-media System for the efficient management of Technical Information
Graduate Research Assistant, Seoul National University, Seoul, Korea, 1996
M.S. thesis topic (Department of Computer Science): I developed a hypermedia system for technical information, including word editor and spread sheet, using Unix X Window/Motif programming.
Research Scientist, Seoul National University Medical Research Center, Winter 2005 - Present
I am researching on the performance evaluation of several image quality metrics in predicting perceptible artifacts of JPEG2000 compressed CT images. I am using a simple mathematical metric (PSNR) and HDR-VPR (High-Dynamic Range Visual Difference Predictor), a perceptual metric modeling the characteristics of the Human Visual System. Based on the metrics' prediction results, we are testifying their feasibility in estimating the visually lossless threshold for such compressions.
Research Scientist, Seoul National University Medical Research Center, Winter 2005 - Present
I am researching on the assessment of the visually lossless threshold (VLT) for JPEG 2000 compression of CT images on a variety of body-parts. As of now, we estimated the VLT of abdomen CT images and compared the compression tolerance of thin- and thick-section abdomen CT images. In addition, we are estimating the VLT of thin-section chest CT images, confined to the lung or the mediastinum/chest wall.
Research Scientist, Seoul National University Medical Research Center, Winter 2005 - Spring 2006
I developed an interactive visualization tool called ConSet, where users can effectively examine concordance among multiple sets at once. It uses enhanced permutation matrix visualization to enable users to easily identify similar sets. In addition to a standard Venn diagram, a new diagram (Fan diagram) was introduced, which allows users to compare two or three sets without inconsistencies.
Director, 3D R&D Center, INFINITT Co., Ltd., Jul. 2005 - Jan. 2006
I had worked as a director of the 3D R & D center in INFINITT Co., Ltd. I directed the center to provide the maintenance of commercial 3D imaging software (Rapidia 3D) and to develop PACS software (INFINITT G3) that is a fully web-based RIS/PACS solution with advanced 3D capabilities all operating on a single platform.
Principal Research Engineer, INFINITT Co., Ltd., Jun. 2004 - Jun. 2005
I customized Rapidia 3D for semiautomatic segmentation of MRI images to break through year-long delay on muscle and bone volume measurements for the FAMUSS project, responding to the requests from Children's National Medical Center. Specific novel measurement features were added to Rapidis 3D, including calculation of cross sectional area (CSA), circumference, three distinct moment of inertia measures (x, y, and polar). In addition, those measurement results were exported in an MDB file for subsequent analyses.
Principal Research Engineer, INFINITT Co., Ltd., Jan. 2003 - Jun. 2005
I worked as a manager for the development of a variety of Rapidia 3D options as follows.
Brain Angio Subtraction
This option provides easy-to-use and fast subtraction of vessels from brain CT angio scan data. It accurately extracts vessels by subtracting bone structures using contrasted and non-contrasted blood vessel data of a patient.
Virtual Colonoscopy
The option provides radiologists with an optimized workflow for colonoscopy interpretation. It creates images similar to those acquired by an actual endoscope navigating the colon and provides various features which support rapid, accurate and non-invasive colon review.
Calcium Scoring
This option provides non-invasive screening tools for heart disease. It segments the coronary arteries from EBCT images, and evaluates the calcium load in the coronary arteries using Agatston and volume scoring algorithms. Powerful report tools are also provided.
Vessel Analysis
This option enables users to quantitatively analyze the vessel of interest. Once users specify a path along a vessel, the vessel is automatically segmented. Then various analysis results are presented including the area of vessel at a given cross-section and the Maximum, Minimum, Average, and Effective cross-section diameters on the path.
Senior Research Engineer, 3D Med Co., Ltd., Feb. 2000 - Dec. 2002
I worked as a manager for the development of commercial 3D imaging software, Rapidia 3D. The 3D imaging is a technology that visualizes 3-dimensional images out of a large quantity of 2D images. Rapidia 3D provides radiologists or clinicians with a practical and easy way to view large number of 2-dimensional slices by generating 3-dimensional images and manipulating them for more effective and accurate diagnosis. Rapidia 3D offers comprehensive image analysis and measurement tools that provide useful and critical information to surgeons and clinicians for their surgical and treatment planning.
Graduate Research Assistant, Seoul National University, Seoul, Korea, Oct. 1998 - Aug. 2001
I designed and implemented a 3D computerized musculoskeletal anatomic atlas in collaboration with Seoul National University College of Medicine, using MS visual C++. I developed an efficient 3D visualization technique for segmented volume data; trunk musculoskeletal structures, upper extremity musculoskeletal structures, head and neck musculoskeletal structures, and spine skeletal structures.
Graduate Research Assistant, Seoul National University, Seoul, Korea, Mar. 1997 - Sep.1998
I participated in the project of image database construction for medical diagnosis assistance. I developed a 2D anatomical human atlas for musculoskeletal structures at lower extremity, using computer graphics techniques.
Graduate Research Assistant, Seoul National University, Seoul, Korea, 1999-2000
Ph.D. thesis topic (School of Computer Science and Engineering): I developed an effective normal estimation method and a new data structure, Slice-based Binary Shell (SBS), for efficient manipulation and rendering of binary volume data.