• Journal of Broadcast Engineering
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• v.22 no.1
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• pp.42-50
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• 2017

A Bit-depth expansion is a method to increase the number of bit. It is getting important as the needs of HDR (High Dynamic Range) display or resolution of display have been increased because the level of luminance or expressiveness of color is proportional to the number of bit in the display. In this paper, we present effective bit-depth expansion algorithm for conventional standard 8 bit-depth content to display in high bit-depth device (10 bits). Proposed method shows better result comparing with recently developed methods in quantitative (PSNR) with low complexity. The proposed method shows 1db higher in PSNR measurement with 40 times faster in computational time.

• ETRI Journal
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• v.44 no.1
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• pp.38-50
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• 2022

This paper presents a study on the use of encoder-derived features in decoder-side depth estimation. The scheme of multiview video encoding does not require the transmission of depth maps (which carry the geometry of a three-dimensional scene) as only a set of input views and their parameters are compressed and packed into the bitstream, with a set of features that could make it easier to estimate geometry in the decoder. The paper proposes novel recursive block splitting for the feature extraction process and evaluates different scenarios of feature-driven decoder-side depth estimation, performed by assessing their influence on the bitrate of metadata, quality of the reconstructed video, and time of depth estimation. As efficient encoding of multiview sequences became one of the main scopes of the video encoding community, the experimental results are based on the "geometry absent" profile from the incoming MPEG Immersive video standard. The results show that the quality of synthesized views using the proposed recursive block splitting outperforms that of the state-of-the-art approach.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.205-207
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• 2020

This paper proposes a novel deep learning-based method to upsample a depth map. Most conventional methods estimate high-resolution depth map by modifying pixel value of given depth map using high-resolution color image and low-resolution depth map. However, these methods cause under- or over-shooting problems that restrict performance improvement. To overcome these problems, the proposed method iteratively performs grid warping scheme which shifts pixel values to restore blurred image for estimating high-resolution depth map. Experimental results show that the proposed method improves both quantitative and visual quality compared to the existing method.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.1
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• pp.112-120
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• 1996

In this study, the porous glass media was utilized as biomass carrier, and the optimum characteristics of this new media in fixed bed biofilm process were investigated. The characteristics of media considered here are a void volume fraction, a specific surface area, and surface characteristics of media. The effect of surface roughness and material could be clearly demonstrated by the fact that the porous glass media showed a good potential for biofilm development. This might results from the fact that biofilm is initially formed in the surface cavities of the media is protect from the shear effect. Therefore, the microcolonies are not readily detached by the fluid shear. In the steady state, biofilm formation along the packing bed depth was different from media to media. The specific area was also an important factor for the attachment of microorganism on the media surface. The specific area was also an important factor for the attachment of microorganism on the media surface. In the case of porous glass media, about $100m^2/m^3$ was enough to obtain a good organic removal efficiency The organic removal efficiency could be improved by increasing the void volume fraction in the reactor, at least 80% was required to obtain a high removal efficiency and prevent clogging. From the analysis of kinetics study, the yield coefficient, Y, was 0.42 mgMLSS/mgSBOD, endogenous respiration coefficient, ke, was $0.12day^{-1}$ and substrate removel coefficient of Mckinney. km, was $16.8hr^{-1}$ for the porous glass media G-2

• The Journal of the Korea Contents Association
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• v.16 no.5
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• pp.720-731
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• 2016

This study aims to understand characteristics and roles of community media in Seoul to discuss the meanings of the media. Community media is constructed based upon the networks of relations of community participants, whose characteristic relations of participants within the network determines the roles and meanings of the media for the community. Research have shown that community media's unique open, participatory, and horizontal communicative structures enable to realize such objects. For this study, we chose Mapo FM to conduct case study based upon network analysis of 'participant network' of the media. In particular, we tried to measure the density and centrality of the network, which can explain the relational characteristics of the networks of the media. In addition, we also conducted in-depth interviews of participants to better understand the problems and meanings of the community media. The findings suggest that unlike the conceptual and theoretical assumptions, the community media under the study lacks of open, participatory, and horizontal ways of participation in the media.

• Journal of Broadcast Engineering
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• v.11 no.1 s.30
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• pp.91-99
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• 2006

Pre-processing is one of image processing techniques to enhance image quality or appropriately convert a given image into another form for a specific purpose. An 8 bit depth map obtained by a depth camera usually contains a lot of noisy components caused by the characteristics of depth camera and edges are also more distorted by the quality of a source object and illumination condition comparing with edges in RGB texture image. To reduce this distortion, we use noise removing filters, but they are only able to reduce noise components, so that distorted edges of depth map can not be properly recovered. In this paper, we propose an algorithm that can reduce noise components and also enhance the quality of edges of depth map by using edges in RGB texture. Consequently, we can reduce errors in multi-view stereo image synthesis process.

• Journal of Broadcast Engineering
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• v.13 no.6
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• pp.796-803
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• 2008

In this paper, we present a depth scaling method for multiview images that could provide an 3D depth that a user prefers. Unlike previous works that change a camera configuration, the proposed method utilizes depth data in order to carry out the scaling of a depth range requested by users. From multivew images and their corresponding depth data, depth data is transformed into a disparity and the disparity is adjusted in order to control the perceived depth. In particular, our method can deal with multiview images captured by multiple cameras, and can be expanded from stereoscopic to multiview images. Based upon a DSCQS subjective evaluation test, our experimental results tested on an automultiscopic 3D display show that the perceived depth is appropriately scaled according to user's preferred depth.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.233-239
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• 2020

Due to the development of digital technology, users can record their daily lives without being restricted by time and space. The trend is growing rapidly, but lifelogging cases are still insufficient. Google's Timeline and domestic application 'Daily' were analyzed through in-depth interviews. Based on the Creating Pleasurable Interface Model, the factors influencing user satisfaction were identified by the Reckard 7-point scale based on the Honeycomb model. The results of the in-depth interviews and the 7-point scale were similar, and we could see what and why users preferred the recording application. This study is meaningful to evaluate the user experience for recording application and analyzing the needs of users obtained through in-depth interviews to assess the usability that provide a service record and recall.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.716-724
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• 2012

In this paper, we propose a fast decision method of maximum coding depth decision and reference frame selection in HEVC. To reduce computational complexity and encoding time of HEVC, two methods are proposed. In the first method, the maximum depth of each coding unit (CU) in a largest CU (LCU) is constrained by using the maximum coding depth used by adjacent LCUs based on the assumption that the spatial correlation is very high and rate-distortion (R-D) cost. And we constrain the number of reference pictures for prediction unit (PU) performing motion estimation by using the motion information of the upper depth PU. The proposed methods reduce computational complexity of the HEVC encoder by constraining the maximum coding depth and the reference frame. We could achieve about 39% computational complexity reduction with marginal bitrate increase of 1.2% in the comparison with HM6.1 HEVC reference software.

• Journal of Digital Convergence
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• v.10 no.2
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• pp.305-310
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• 2012

As the era of change that has developed a variety of media. But no matter how hi-tech media it, even though several of the previous circular forms of media have evolved from. Jay David Bolter and Richard Grusin them academically for "old media remediation will use," he explains. The middle of media, especially games remediation nature of the game, the game plan, game content, game machines, etc. in various parts of the outward form, there is remediation characteristics. The use of these remediation allows users to facilitate access to the media, and more importantly are able to adapt quickly to the game controls. And Increase the fun of the game, given the immersion for the game that enhance the role is. Remediation of the game against a variety of elements in the game if they utilize in-depth research on the development of the game has been suggested that the role is a lot.