Publications by Year: 2009

Kim, J., Hong, K., Jung, J. - H., Park, G., Lim, J., Kim, Y., Hahn, J., et al. (2009). High definition integral floating display with multiple spatial light modulators. Proc. SPIE. 7237, Stereoscopic Displays and Applications XX. Publisher's Version
Hong, K., Hong, J., Kang, J. - M., Jung, J. - H., Park, J. - H., & Lee, B. (2009). Improved Three-Dimensional Depth Extraction Using Super Resolved Elemental Image Set. Digital Holography and Three-Dimensional Imaging . Optical Society of America. Publisher's VersionAbstract
We proposed a new method to improve depth extraction in integral imaging using super-resolution algorithm. Simulation results show the extractable depth resolution is enhanced after the super-resolution procedure.
Jung, J. - H., Park, G., Kim, Y., & Lee, B. (2009). 360-degree viewable cylindrical integral imaging system using electroluminescent films. 9th International Meeting on Information Display (IMID 2009) . The Society for Information Display.
Merck Young Scientist Award
Lee, B., Kim, Y., & Jung, J. - H. (2009). Two-dimensional/three-dimensional convertible display device using surface light source array. Korean Patent . KR Patent No. 10-0918670.
Lee, B., Kim, Y., Kim, J., Jung, J. - H., Kang, J., & Choi, H. (2009). Three-dimensional display system and method for using electrically moving pinhole array. Korean Patent . KR Patent No. 10-0928332.
Kang, J., Jung, J. - H., Lee, B., & Park, J. - H. (2009). Object-based integral imaging depth extraction using segmentation. Korean Journal of Optics and Photonics , 20 (2), 94-101. Publisher's VersionAbstract
A novel method for the reconstruction of 3D shape and texture from elemental images has been proposed. Using this method, we can estimate a full 3D polygonal model of objects with seamless triangulation. But in the triangulation process, all the objects are stitched. This generates phantom surfaces that bridge depth discontinuities between different objects. To solve this problem we need to connect points only within a single object. We adopt a segmentation process to this end. The entire process of the proposed method is as follows. First, the central pixel of each elemental image is computed to extract spatial position of objects by correspondence analysis. Second, the object points of central pixels from neighboring elemental images are projected onto a specific elemental image. Then, the center sub-image is segmented and each object is labeled. We used the normalized cut algorithm for segmentation of the center sub-image. To enhance the speed of segmentation we applied the watershed algorithm before the normalized cut. Using the segmentation results, the subdivision process is applied to pixels only within the same objects. The refined grid is filtered with median and Gaussian filters to improve reconstruction quality. Finally, each vertex is connected and an object-based triangular mesh is formed. We conducted experiments using real objects and verified our proposed method.
Jung, J. - H., Park, G., Kim, J., Kang, J., & Lee, B. (2009). Three-dimensional conversion of two-dimensional movie using optical flow and normalized cut. Korean Journal of Optics and Photonics , 20 (1), 16-22. Publisher's VersionAbstract
We propose a method to convert a two-dimensional movie to a three-dimensional movie using normalized cut and optical flow. In this paper, we segment an image of a two-dimensional movie to objects first, and then estimate the depth of each object. Normalized cut is one of the image segmentation algorithms. For improving speed and accuracy of normalized cut, we used a watershed algorithm and a weight function using optical flow. We estimate the depth of objects which are segmented by improved normalized cut using optical flow. Ordinal depth is estimated by the change of the segmented object label in an occluded region which is the difference of absolute values of optical flow. For compensating ordinal depth, we generate the relational depth which is the absolute value of optical flow as motion parallax. A final depth map is determined by multiplying ordinal depth by relational depth, then dividing by average optical flow. In this research, we propose the two-dimensional/three-dimensional movie conversion method which is applicable to all three-dimensional display devices and all two-dimensional movie formats. We present experimental results using sample two-dimensional movies.
Park, G., Jung, J. - H., Hong, K., Kim, Y., Kim, Y. - H., Min, S. - W., & Lee, B. (2009). Multi-viewer tracking integral imaging system and its viewing zone analysis. Opt. Express , 17 (20), 17895–17908 . OSA. Publisher's VersionAbstract

We propose a multi-viewer tracking integral imaging system for viewing angle and viewing zone improvement. In the tracking integral imaging system, the pickup angles in each elemental lens in the lens array are decided by the positions of viewers, which means the elemental image can be made for each viewer to provide wider viewing angle and larger viewing zone. Our tracking integral imaging system is implemented with an infrared camera and infrared light emitting diodes which can track the viewers&\#x2019; exact positions robustly. For multiple viewers to watch integrated three-dimensional images in the tracking integral imaging system, it is needed to formulate the relationship between the multiple viewers&\#x2019; positions and the elemental images. We analyzed the relationship and the conditions for the multiple viewers, and verified them by the implementation of two-viewer tracking integral imaging system.

Jung, J. - H., Kim, Y., Kim, Y., Kim, J., Hong, K., & Lee, B. (2009). Integral imaging system using an electroluminescent film backlight for three-dimensional-two-dimensional convertibility and a curved structure. Appl. Opt. , 48, 998–1007 . OSA. Publisher's VersionAbstract
We propose a thin and compact integral imaging system using electroluminescent (EL) films as backlight. EL film has the advantage that it can operate continuously even when it is cut or punctured. Using this characteristic, we generate an array of pinholes on EL film to form a point light-source array for reconstructing three-dimensional (3D) images based on integral imaging. The EL pinhole film is attached on another EL film and they are electrically controlled to generate a point light-source array or a surface light source; hence, the system converts between 3D and two-dimensional (2D) modes. Taking advantage of the flexibility of EL films, we also propose a flexible 3D/2D convertible integral imaging system with a wide viewing angle using a curved EL film. We explain the principle of the proposed methods and present experimental results.
Kim, Y., Park, G., Jung, J. - H., Kim, J., & Lee, B. (2009). Color moiré pattern simulation and analysis in three-dimensional integral imaging for finding the moiré-reduced tilted angle of a lens array. Appl. Opt. , 48, 2178–2187 . OSA. Publisher's VersionAbstract

We propose a color moiré pattern simulation and analysis method in integral imaging for finding the moiré-reducing tilted angle of a lens array. According to the tilted angle, the color moiré patterns are simulated on the assumption of ray optics. The spatial frequencies of the color moiré patterns are numerically analyzed using a spatial Fourier transform for finding the optimal angle where the moiré is reduced. With the proposed technique the visualization of the color moiré pattern and its analysis are enabled. The moiré-reduced three-dimensional images can be displayed. The principle of the proposed method, simulation results, and their analysis are provided. Experimental results verify the validity of the proposed method.