Gi Mun Um

Virtual View Generation Based on Multiple Images

A framework for virtual view synthesis based on multiple images is presented in this paper. Compared to conventional view synthesis based on stereoscopic image pairs, a postprocessing algorithm for disparity refinement is added to exploit information contained in multiple images captured with a multi-view camera configuration. The principle for disparity refinement is examined, leading to the development of a novel algorithm. Experimental results show that the newly developed algorithm can improve image quality of synthesized virtual views with a PSNR gain of up to 0.65 dB.

Investigation on the effects of disparity-based asymmetrical filtering of stereoscopic video

Current binocular stereoscopic displays cause visual discomfort when the objects with large disparities are present in the scene. With this technique, the improvement of visual comfort has been reported by blurring far background and foregrounds in the scene. However, this technique has a drawback of degrading overall image quality. To lesson visual discomfort caused by large disparities while maintaining high-perceived image quality, we use a novel disparity-based asymmetrical filtering technique. Asymmetrical filtering, which refers to the filtering applied to the image of one eye only, has been showen to maintain the sharpness of a stereoscopic image, provided that the amount of filtering is low. Disparity-based asymmetrical filtering usese the disparity information in a stereoscopic image for controlling the severity of blurring. We investigated the effects of this technique on stereoscopic video by measuring visual comfort and apparent sharpness. Our results indicate that disparity-based asymmetrical filtering does not always improve visual comfort but it maintains image quality.

Depth adjustment of ROI using scalable multiplexing in 3D display

In this paper, we presents a depth adjustment technique that controls depth of region of interest using scalable multiplexing in 3D display. Autostereoscopic displays offer different 3D images depending on the viewing direction. In order to display various viewpoint images on the autostereoscopic display at the same time, we usually divide the space of display panel spatially. This is called spatial multiplexing. However, this spatial multiplexing causes degradation of each viewpoint image resolution. Each viewpoint source is resized with the ratio of the inverse proportion to the number of view due to limited resolution of 3D display. When the images are downscaled with a certain ratio and, the downscaling ratio of the object of interest is bigger than that of the others, the object of interest is enlarged more than the other region without any loss. Moreover, enlarged object region covers the other regions belong to the background of image. In this case, the covered area can offer enough space to make the object that has binocular disparity without any interpolation of holes. It can also control the objects depth in the 3D scene.

Virtual control of optical axis for streo HDTV

In stereoscopic television, there is a trade-off between visual comfort and 3D impact with respect to the baseline-stretch of 3D camera. It has been reported that an optimal condition can be reached when we set the baseline-stretch at about the distance of human pupils1. However, we cannot get such distance in case that the sizes of the lens and CCD module are big. In order to overcome this limitation, we attempt to control the baseline-stretch of stereoscopic camera by synthesizing virtual views at the desired location of interval between two cameras. Proposed technique is based on the stereo matching and view synthesis techniques. We first obtain a dense disparity map using a hierarchical stereo matching with the edge-adaptive shifted window. And then we synthesize virtual views using the disparity map. Simulation results with various stereoscopic images demonstrate the effectiveness of the proposed technique.