김규헌 교수

A point cloud visualizes information by placing a voxel with a color value and a position value in a three-dimensional space. Since a point cloud uses hundreds of thousands or millions of points to visualize information, a large number of bits is needed compared to existing 2D media. Therefore, it is essential to compress point data for transmission and storage. The Moving Picture Expert Group (MPEG) is developing a point cloud compression method based on 2D video that takes advantage of the ben

β-Ga2O3 is a highly promising semiconductor for a deep ultraviolet (UV) emitter owing to its wide band gap, which significantly varies in the range of 4.49–4.74 eV because of its optical trirefringence in the monoclinic crystal structure (C2h). However, dominant photoluminescence (PL) emissions occur far below the band gap. These PL peaks at 3.0 and 3.5 eV were investigated by employing photoluminescence excitation spectroscopy. Intriguingly, the PL was found to be highly polarized along the (10

We propose an image retrieval system using the Borda count method in combining multiple experts (CME). It combines color-, shape- and texture-based retrieval systems. CME method can complementarily combine results of each retrieval system, which uses different features. There are some problems when the Borda count method in pattern recognition is applied to image retrieval. Thus, we propose a modified Borda count method to solve these problems. In the experiment our method reduces false positive

could be achieved at 77 K. These enhancements strongly indicate that the previously reported high off-state current was originated from interfacial defects formed at the metal-Te contact interface. Although further studies concerning this interface are still necessary, the findings herein demonstrate that the major obstacles hindering the use of Te for ultrathin p-channel device applications can be eliminated by proper process optimization.

Extensive research has been conducted in the past to determine age, gender, and words spoken in Bangla speech, but no work has been conducted to identify the regional language spoken by the speaker in Bangla speech. Hence, in this study, we create a dataset containing 30 h of Bangla speech of seven regional Bangla dialects with the goal of detecting synthesized Bangla speech and categorizing it. To categorize the regional language spoken by the speaker in the Bangla speech and determine its auth

A point cloud acquired through a Light Detection And Ranging (LiDAR) sensor can be illustrated as a continuous frame with a time axis. Since the frame-by-frame point cloud has a high correlation between frames, a higher compression efficiency can be obtained by using an inter-prediction scheme, and for this purpose, Geometry-based Point Cloud Compression (G-PCC) in the Moving Picture Expert Group (MPEG) opened Inter-Exploratory Model (Inter-EM) which experiments on continuous LiDAR based point c

Fast binary dilation and erosion algorithms using run-length encoding (RLE) are proposed. RLE is an alternative way of representing a binary image using a run, which is a sequence of ‘1’ pixels. First, we derive the run-based representation of dilation and erosion and then present the full steps of the proposed algorithms in detail.

From stitching video sequences point of view, an existing image stitching technique may have limitations on object movement or loss in the stitched video sequence due to the different parallax of the individual video sequences. Also, an existing image stitching technique have higher computational complexity and have matching accuracy limitations in obtaining descriptors for many factors. Therefore, this paper proposes an edge-based weight minimum error seam method in order to overcome the limita

There have been lots of technical developments in broadcasting field since 1990s. Providing high quality video and audio is one improvement and supporting mobile reception in a high-speed vehicle is another. Terrestrial Digital Multimedia Broadcasting (T-DMB) is one of the successfully deployed technologies to provide mobile broadcasting service. One of the major breakthroughs achieved by T-DMB in addition to robust vehicular reception is a system architecture naturally enabling integrated inter

Various methods are used to provide three-dimensional television (3DTV) services over a terrestrial broadcasting network. However, these services cannot provide high-quality 3D content to consumers. It is because current terrestrial broadcast networks are allocated with limited bandwidths to transmit 3D content while 3D content requires larger bandwidth compared to that of 2D content. To overcome this limitation, this paper proposes a hybrid 3DTV broadcasting system, which utilizes both a terres

Point cloud content is widely used to store and represent 3D volumetric objects with a complex and detailed representation from any direction of view. However, the amount of data needed for point cloud content is much larger than that of 2D representations. To overcome this difficulty, MPEG has started to develop a Video-based Point Cloud Compression (V-PCC) that is designed by projecting point cloud content into 2D content and compressing the 2D content using conventional 2D video codecs. Compr

Since multimedia data is widely used in many fields, research is needed on how to search that data. As a method of retrieving multimedia data, especially for image data, content based image retrieval (CBIR) systems have obtained lots of interest. In order to develop CBIR systems, many different properties of an image have been considered for methods of retrieving image data such as colour, texture, shape, etc. The paper proposes a simple and efficient image retrieval algorithm, which retrieves i

A lot of 3D contents haven been widely used for multimedia services, however, real 3D video contents have been adopted for a limited applications such as a specially designed 3D cinema. This is because of the difficulty of capturing real 3D video contents and the limitation of display devices available in a market. However, diverse types of display devices for stereoscopic video contents for real 3D video contents have been recently released in a market. Especially, a mobile phone with a stereos