Eung-Don Lee

Upstream Channel Synchronization for Cable Modem System

The upstream of digital cable modem is a burst mode transmission system, where a burst contains the preamble and data. In this paper, we consider algorithms for the symbol timing, carrier frequency- and phase-offset recovery for the upstream cable modem, that are compliant to DOCSIS 2.0. Several algorithms are tested and verified to find the best algorithm for each of the three recovery blocks, respectively. To fit to the DOCSIS specification, Oerder & Meyrs is chosen for the timing recovery algorithm, Mengali & Morellis is chosen for the carrier frequency-offset recovery algorithm and Cartwrights is chosen for blind carrier phase recovery. We decide the optimal preamble length for these algorithms and check the error variance. Finally, we show the error performance of the entire system.

Real-time Temporal Synchronization and Compensation in Stereoscopic Video

In this paper, we propose a real-time temporal synchronization and compensation algorithm in stereoscopic video. Many temporal asynchronies are caused in the video editing stage and due to different transmission delays. These temporal asynchronies can degrade the perceived 3D quality. The goal of temporal alignment is to detect and to measure the temporal asynchrony and recover synchronization of the two video streams. In order to recover synchronization of the two video streams, we developed a method to detect asynchronies between the left and the right video streams based on a novel spatiogram information, which is a richer representation, capturing not only the values of the pixels but their spatial relationships as well. The proposed novel spatiogram additionally includes the changes of the spatial color distribution. Furthermore, we propose a block-based method for detection of the pair frame instead of one frame-based method. Various 3D experiments demonstrate the effectiveness of the proposed method.

A method of quantifying moirés on 3D displays

A method of quantifying the amount of moirés in contact-type 3-D displays is described. The color moirés in the displays are induced by the periodic blocking of a part of each pixel on the panel by the boundary lines or the barrier lines consisting of the viewing zone forming optics. The method starts calculating the intensity of an image laden with moirés and that of the image with no moirés. The moirés contrast is defined as the intensity difference of the two images. The contrast values match well with those from the simulated moirés for the crossing angle range of 0° to 20°.

A Real-time Dual-mode Temporal Synchronization and Compensation based on Reliability Measure in Stereoscopic Video

In this paper, a real-time dual-mode temporal synchronization and compensation method based on a new reliability measure in stereoscopic video is proposed. The goal of temporal alignment is to detect the temporal asynchrony and recover synchronization of the two video streams. The accuracy of the temporal synchronization algorithm depends on the 3DTV contents. In order to compensate the temporal synchronization error, it is necessary to judge whether the result of the temporal synchronization is reliable or not. Based on our recently developed temporal synchronization method(1), we define a new reliability measure for the result of the temporal synchronization method. Furthermore, we developed a dual-mode temporal synchronization method, which uses a usual texture matching method and the temporal spatiogram method(1). The new reliability measure is based on two distinctive features, a dynamic feature for scene change and a matching distinction feature. Various experimental results show the effectiveness of the proposed method. The proposed algorithms are evaluated and verified through an experimental system implemented for 3DTV.

Automatinc synchronization of stereoscopic video for 3DTV broadcasting system

This paper proposes an algorithm to automatically detect synchronization error that can be occurred in the stereoscopic video system. Specially, this paper is aiming toward 3DTV broadcasting system that requires a real-time operation with high accuracy. Accordingly, we propose new similarity calculation algorithm by applying the spatiogram concept, which is proper to the sync error detection at stereoscopic video with real-time operation. In this paper, the spatiogram includes temporal information to increase an accuracy of sync error detection. This paper also introduces an implementation of stereoscopic video synchronizer for the purpose of practical use, which performs the sync error correction function. Finally, the proposed algorithms are evaluated and verified through an implemented of 3DTV experimental system.