• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.265-272
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• 2015

A new technology on video frame rate up-conversion (FRUC) is presented by combining the median filter and motion estimation (ME) with an occlusion detection (OD) method. First, ME is performed to have a motion vector. Then, the OD method is used to refine motion vector in the occlusion region. Since the wrong motion vector can be obtained with high possibility in the occluded area, a median filtering that less depends on the motion vector is applied to that area, and since the motion vector is continuous and robust in the non-occluded area, BDMC(Bi-Directional Motion Compensated interpolation) is applied to obtain interpolated image in that area. BDMC using the bi-directional motion vectors achieves good results when continuity and robustness of the motion vector is higher. Experimental results show that the proposed algorithm provides better performance than the conventional approach. The average gain of PSNR (Peak Signal to Noise Ratio) is approximately 0.16 dB in the test sequences compared with BDMC.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.171-182
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• 2015

HEVC can increase the coding efficiency significantly compared with H.264/AVC however it requires much larger computational complexities in both encoder and decoder. In this paper, the decision process of inter-prediction modes in the HEVC reference software has been studied and a fast algorithm to reduce the computational complexity of encoder and decoder is introduced. The proposed scheme introduces a early decision criteria using the outputs of uni-directional predictions to skip the bi-directional prediction estimation. From the experimental results, it was proven that the proposed method can reduce the encoding complexity by 12.0%, 14.6% and 17.2% with 0.6%, 1.0% and 1.5% of coding efficiency penalty, respectively. In addition, the ratio of bi-directional prediction mode was reduced by 6.3%, 11.8% and 16.6% at the same level of coding efficiency penalty, respectively, which should lead to the decoder complexity reduction. Finally, the effects of the proposed scheme are maintained regardless of the use of the early skip decision algorithm which is implemented in the HEVC reference software.

• Journal of Broadcast Engineering
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• v.14 no.3
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• pp.342-356
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• 2009

This paper presents a vote decision-based deinterlacing scheme for false directional error correction(VDD) to convert interlaced signal into non-interlaced signal using only one fields. The VDD using the vote decision goes through four steps process. The first step extracts regions having doubt of false edge using MM-ELA method. In these regions, the edge direction is decided by the majority vote using upper adjacent pixels's information through the second step. But, we still have undecided directions, which will be decided by the majority vote and the directional average decision at the third step. This step preserves the edge directions and minimizes visual degradation. Finally, the last step interpolates undecided pixels using DOI method which can consider the fine edge direction. Although the VDD with hierarchical structure has a high complexity, it can extract delicate edge compared to other pixel-by-pixel or window-by-window deinterlacing algorithms. Simulation results show that it has significantly improved both the subjective and objective qualities of the reconstructed images.

• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.807-810
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• 2009

This paper deals with a real-time image based relighting system for tangible video teleconference. The proposed image based relighting system renders the extracted human object using the virtual environmental images. The proposed system can homogenize virtually the lighting environments of remote users on the video teleconference, or render the humans like they are in the virtual places. To realize the video teleconference, the paper obtains the 3D object models of users in real-time using the controlled lighting system. In this paper, we use single color camera and synchronized two directional flash lights. Proposed system generates pure shading images using on and off flash images subtraction. One pure shading reflectance map generates a directional normal map from multiplication of each reflectance map and basic normal vector map. Each directional basic normal map is generated by inner vector calculation of incident light vector and camera viewing vector. And the basic normal vector means a basis component of real surface normal vector. The proposed system enables the users to immerse video teleconference just as they are in the virtual environments.

• Journal of Broadcast Engineering
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• v.21 no.4
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• pp.472-483
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• 2016

This paper proposes a blocking artifacts detection algorithm in frequency domain for MC-FRUC (Motion Compensated Frame Rate Up-Conversion). Conventional MC-FRUC algorithms occur blocking artifacts near interpolated block boundaries since motion compensation is performed from block-based motion vector. For efficiently decreasing blocking artifacts, this paper analyses frequency characteristics of the interpolated frame and reduces blocking artifacts on block boundaries. In experimental results the proposed method shows better subjective quality than some conventional FRUC method and also increases the PSNR(Peak Signal to Noise Ratio) value on average 0.45 dB compared with BDMC(Bi-Directional Motion Compensation).

• Journal of Broadcast Engineering
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• v.13 no.5
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• pp.636-650
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• 2008

DTV has a great advantage as compared to Analog TV in picture quality under low reception field strength. Various high quality tuners have been developed to result in much smaller Noise Figure of the receivers and many trials for receiving DTV signal through indoor antenna. In this paper, results of intensive field tests on the indoor reception of DTV are presented. Tests were carried out around Seoul-Gyeonggi Metropolitan area. Commercial directional and omni-directional antennas and 5th generation receiver were used for reception availability tests. The effects of heights, locations, and types of the house as well as the distance to the transmitter on the reception performances are analyzed. Our test results will be applied to improve the indoor reception environment of DTV.

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.785-799
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• 2017

One of the most widely used image media in recent years, omni-directional panorama images are attracting much attention. Since this image is ultra-high value-added, the intellectual property of this image must be protected. In this paper, we propose a blind digital watermarking method for this image. In this paper, we assume that the owner of each original image may be different, insert different watermark data into each original image, and extract the watermark from the projected image, which is a form of service of omni- directional panorama image. Therefore, the main target attack in this paper is the image distortion which occurs in the process of the omni- directional panorama image. In this method, SIFT feature points of non-stitched areas are used, and watermark data is inserted into data around each feature point. We propose two methods of using two-dimensional DWT coefficients and spatial domain data as data for inserting watermark. Both methods insert watermark data by QIM method. Through experiments, these two methods show robustness against the distortion generated in the panorama image generation process, and additionally show sufficient robustness against JPEG compression attack.

• Journal of Broadcast Engineering
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• v.15 no.6
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• pp.815-829
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• 2010

In this paper, we propose a new $4{\times}4$ intra coding method by unidirectional prediction for improvement of intra-frame coding efficiency of H.264/AVC. There are $4{\times}4$, $8{\times}8$, and $16{\times}16$ intra prediction modes in the current H.264/AVC. For the $4{\times}4$ intra prediction, coding efficiency is achieved by accurate prediction with small block size in relatively complicated regions, and the $16{\times}16$ intra prediction method can predict more accurately compared to $4{\times}4$ intra prediction with only one directional information in relatively homogeneous regions. We propose a unidirectional $4{\times}4$ intra prediction method adopting a small-size prediction and one directional prediction approaches. In order to improve coding efficiency, the proposed method is conducted by $4{\times}4$ block and their prediction directions are all the same, resulting that we need to send only one directional information for each macroblock. For intra-frame coding setting, we achieve 10.47% and 1.57% coding efficiency in BD-bitrate for only $16{\times}16$ intra mode and $4{\times}4$, $16{\times}16$ intra mode, respectively.

• Journal of Broadcast Engineering
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• v.14 no.1
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• pp.59-69
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• 2009

A bi-directional symmetric prediction technique has been developed to improve coding efficiency of B-slice and to reduce the computational complexity required to estimate two motion vectors. On the contrary to the conventional bi-directional mode which encodes both forward and backward motion vectors, it only encodes a single forward motion vector, and the missing backward motion vector is derived in a symmetric way from the forward motion vector using temporal distance between forward/backward reference frames to and from the current B picture. Since the backward motion vector is derived from the forward motion vector, it can halve the computational complexity for motion estimation, and also reduces motion vector data to encode. This technique always derives the backward motion vector from the forward motion vector, however, there are cases when the forward motion vector is better to be derived from the backward motion vector especially in scene changes. In this paper, we generalize the idea of the symmetric coding with forward motion vector coding, and propose a new symmetric coding with backward motion vector coding and adaptive selection between the conventional symmetric mode and the proposed symmetric mode based on rate-distortion optimization.

• Journal of the Society of Disaster Information
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• v.12 no.3
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• pp.235-241
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• 2016

Recently our country was entering a high-tech society with social and economic development. However, the individual's ability to respond to disasters is lowered by the increase in complexity society. Accurate situation assessment and disaster response by a margin of personal information that can identify when a disaster has been difficult. Until now, by leveraging Standard speaker was the emergency alert broadcast. However, it was difficult to have regular speakers reverberation, a distinct attenuation of sound by listening to the sound, etc. due to the reflection of sound. By using a directional speaker that is characteristic of the sound attenuation of sound is straight to solve this problem and obtain feedback on measures that can effectively provide the oocytes to a valid information on a disaster situation and the evacuation.