• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.616-624
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• 2009

This paper presents a 3D stereoscopic TIP (Tour Into Picture) for Korean classical paintings being composed of persons, boat, and landscape. Unlike conventional TIP methods providing 2D image or video, our proposed TIP can provide users with 3D stereoscopic contents. Navigating a picture with stereoscopic viewing can deliver more realistic and immersive perception. The method firstly makes input data being composed of foreground mask, background image, and depth map. The second step is to navigate the picture and to obtain rendered images by orthographic or perspective projection. Then, two depth enhancement schemes such as depth template and Laws depth are utilized in order to reduce a cardboard effect and thus to enhance 3D perceived depth of the foreground objects. In experiments, the proposed method was tested on 'Danopungjun' and 'Muyigido' that are famous paintings made in Chosun Dynasty. The stereoscopic animation was proved to deliver new 3D perception compared with 2D video.

• Journal of Korea Multimedia Society
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• v.13 no.4
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• pp.575-581
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• 2010

With widespread use of the Internet and improvements in streaming media and compression technology, digital music, video, and image can be distributed instantaneously across the Internet to end-users. However, most conventional Digital Right Management are often not secure and not fast enough to process the vast amount of data generated by the multimedia applications to meet the real-time constraints. The SVC offers temporal, spatial, and SNR scalability to varying network bandwidth and different application needs. Meanwhile, for many multimedia services, security is an important component to restrict unauthorized content access and distribution. This suggests the need for new cryptography system implementations that can operate at SVC. In this paper, we propose a new scrambling encryption for reserving the characteristic of scalability in MPEG4-SVC. In the base layer, the proposed algorithm is applied and performed the selective scambling. And it encrypts various MVS and intra-mode scrambling in the enhancement layer. In the decryption, it decrypts each encrypted layers by using another encrypted keys. Throughout the experimental results, the proposed algorithms have low complexity in encryption and the robustness of communication errors.

• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.738-749
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• 2011

In this paper, we study QoS(Quality of Service) control protocols and the effect using MAC/PHY parameters of client device in mobile network. We proposes the way of controling the bit-rate by estimating the channel condition of the client with measured MAC/PHY parameters which is sent from the client. With the proposed method, more accurate available bit-rate can be estimated compared to conventional protocol, RTCP(Real-time Transport Control Protocol). The accurate bit-rate estimation can decrease wasted bit-rate and transport delay. In the result of the advantages, the transported video quality can be enhanced. In this paper, we show the effects of enhancement using client's the field data measured in WiMAX.

• Journal of Broadcast Engineering
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• v.18 no.4
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• pp.647-650
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• 2013

HEVC RExt(High Efficiency Video Coding Range Extension) set a goal to support RGB/YUV 4:2:2 4:4:4 color sampling and over 10 bit-depth images. Unlike the previous 4:2:0 color sampling images, RGB images have the high correlation in inter-color planes. Using this characteristic, some methods which are contributed in JCT-VC standardization meetings estimate the pixel values of inter-color plane. But when we use the estimation of inter-color plane in RGB images, high frequency components of RGB images are caused to reduce the coding efficiency because they usually have the low inter-color plane correlation. Therefore, in this paper, we propose an adaptive low pass filtering method in the inter-color plane estimation. Using this method, we can improve the estimation efficiency of inter-color plane in RGB images. The experimental results with HEVC RExt RGB test sequences show that the proposed method has 0.6% BD(Bjontegaard Distortion)-rate gain and some increased complexity compared to the previous inter-color plane estimation method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1478-1486
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• 2016

This paper introduces technical methods to improve the accessibility and usability of a WebRTC video conference (VC) application. Simplified login is essential, by applying such as single sign-on (SSO) to improve the accessibility of VC applications. High usability and manageability are also necessary to attract more users, enhance user experiences, and save service management cost. The proposed VC application leverages SAML-based federated identity management (FIM) to enable higher service accessibility. Users can access the application with their organizational ID and SSO authentication. The FIM eases user ID management and indirectly strengthens privacy information protection. Proposed web application has high usability and manageability because users and/or administrators can easily create, join, monitor, or tear down VC sessions through RESTful web service (REST API). We verify the feasibility of the VC application after illustrating the SAML-based identity federation and the designed REST API.

• Journal of the Institute of Convergence Signal Processing
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• v.18 no.2
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• pp.62-67
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• 2017

In this paper, we propose a fast motion estimation algorithm which is important in performance of video encoding. Even though so many fast algorithms for motion estimation have been published due to tremendous computational amount of full search algorithm, efforts for reducing computations of motion estimation still remain. In the paper, we propose an algorithm that reduces unnecessary computations only, while keeping prediction quality the same as that of the full search. The proposed algorithm does not calculate block matching error for each candidate directly to find motion vectors but divides the calculation procedure into several steps and calculates partial sum of block errors for candidates with high priority. By doing that, we can find the minimum error point early and get the enhancement of calculation speed by reducing unnecessary computations. The proposed algorithm uses smaller computations than conventional fast search algorithms with the same prediction quality as the full search algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.2
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• pp.206-212
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• 2006

Many image and video compression algorithms work by splitting the input image into blocks and producing variable-length coded bits for each block data. If variable-length coded data are transmitted consecutively, then the resulting coder is highly sensitive to channel errors. Therefore, most image and video techniques for providing some protection to the stream against channel errors usually involve adding a controlled amount of redundancy back into the stream. Such redundancy might take the form of resynchronization markers, which enable the decoder to restart the decoding process from the known state, in the event of transmission errors. The Error Resilient Entropy Code (EREC) is a well known method which can regain synchronization without any redundant information to convert from variable-length code to fixed-length code. This paper proposes an enhancement to EREC, which greatly improves its transmission ability for the compressed image quality without any redundant bits in the event of errors. The simulation result shows that the both objective and subjective quality of transmitted image is enhanced compared with the existing EREC at the same BER(Bit Error Rate).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.1
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• pp.1-8
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• 2024

On-device AI technology, which can operate AI models at the edge devices to support real-time processing and privacy enhancement, is attracting attention. As intelligent IoT is applied to various industries, services utilizing the on-device AI technology are increasing significantly. However, general deep learning models require a lot of computational resources for inference and learning. Therefore, various lightweighting methods such as quantization and pruning have been suggested to operate deep learning models in embedded edge devices. Among the lightweighting methods, we analyze how to lightweight and apply deep learning models to edge computing devices, focusing on pruning technology in this paper. In particular, we utilize dynamic and static pruning techniques to evaluate the inference speed, accuracy, and memory usage of a lightweight AI vision model. The content analyzed in this paper can be used for intelligent video control systems or video security systems in autonomous vehicles, where real-time processing are highly required. In addition, it is expected that the content can be used more effectively in various IoT services and industries.

• Convergence Security Journal
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• v.24 no.3
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• pp.143-151
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• 2024

IP cameras allow users to view live video regardless of their location. Due to this advantage, they are used in homes to monitor infants, pets, and the elderly, and they are widely utilized in companies for physical security control and monitoring of secure areas, such as data centers and warehouses. However, IP cameras that lack appropriate security measures can be eavesdropped on by malicious attackers. This study demonstrates that hacking attacks can be executed by exploiting various security vulnerabilities in IP cameras, including brute force attacks. Accordingly, we propose an architecture that addresses these vulnerabilities, suggesting measures to enhance the security of IP cameras. Also, we shows that the proposed method can safely and effectively provide video information encryption and user authentication for IP cameras through security verification and availability evaluation.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.273-282
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• 1992

The purpose of this study was to propose the utility which was evaluated the digital image processing and clinical application of the videodensitomery. The experiments were performed with IBM-PC/16bit-AT compatible, video camera(CCdtr55, Sony Co., Japan), an color monitor(MultiSync 3D, NEC, Japan) providing the resolution of 512×480 and 64 levels of gray. Sylvia Image Capture Board for the ADC(analog to digital converter) was used, composed of digitized image from digital signal and the radiographic density was measured by 256 level of gray. The periapical radiograph(Ektaspeed EP-21, Kodak Co., U. S. A) which was radiographed dried human mandible by exposure condition of 70 kVp and 48 impulses, was used for primary X-ray detector. And them evaluated for digitzed image by low and high pass filtering, correlations between aluminum equivalent values and the thickness of aluminum step wedge, aluminum equivalent values of sound enamel, dentin, and alveolar bone, the range of diffuse density for gray level ranging from 0 to 255. The obtained results were as follows: 1. The edge between aluminum steps of digitized image were somewhat blurred by low pass filtering, but edge enhancement could be resulted by high pass filtering. Expecially, edge enhancement between distal root of lower left 2nd molar and alveolar lamina dura was observed. 2. The correlation between aluminum equivalent values and the thickness of aluminum step wedge was intimated, yielding the coefficient of correlation r=0.9997(p<0.00l), the regression line was described by Y=0.9699X+0.456, and coefficient of variation amounting to 1.5%. 3. The aluminum equivalent values of sound enamel, dentin, and alvolar bone were 15.41㎜, 12.48㎜, 10.35㎜, respectively. 4. The range of diffuse density for gray level ranging from 0 to 255 was wider enough than that of photodenstiometer to be within the range of 1-4.9.