• The Journal of Information Technology
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• v.7 no.2
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• pp.93-104
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• 2004

Sports scene is characterized by large amount of global motion due to pan and zoom of camera motion, and includes many small objects moving independently. Some short period of sports games is thrilling to televiewers, and important to producers. At the same time that kinds of scenes exhibit exceptionally dynamic motions and it is very difficult to analyze the motions with conventional algorithms. In this thesis, several algorithms are proposed for global motion analysis on these dynamic scenes. It is shown that proposed algorithms worked well for motion compensation and panorama synthesis. When cascading the inter frame motions, accumulated errors are unavoidable. In order to minimize these errors, interpolation method of motion vectors is introduced. Affined transform or perspective projection transform is regarded as a square matrix, which can be factorized into small amount of motion vectors. To solve factorization problem, we preposed the adaptation of Newton Raphson method into vector and matrix form, which is also computationally efficient. Combining multi frame motion estimation and the corresponding interpolation in hierarchical manner enhancement algorithm of motion parameters is proposed, which is suitable for motion compensation and panorama synthesis. The proposed algorithms are suitable for special effect rendering for broadcast system, video indexing, tracking in complex scenes, and other fields requiring global motion estimation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.7
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• pp.52-60
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• 2008

The deblocking filter in the H.264/AVC video coding standard helps to reduce the blocking artifacts produced in the decoding process. But it consumes one third of the computational complexity in H.624/AVC decoder, which advocates an efficient design of a hardware accelerator for filtering. This paper proposes an architecture of deblocking filter using two filters and some registers for data reuse. Our architecture improves the throughput and minimize the number of external memory access by increasing data reuse. After initialization, two filters are able to perform filtering operation simultaneously. It takes only 96 clocks to complete filtering for one macroblock. We design and synthesis our architecture using Dongbuanam $0.18{\mu}m$ standard cell library and the maximum clock frequency is 200MHz.

• Smart Media Journal
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• v.4 no.1
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• pp.9-15
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• 2015

Nonverbal communications such as eye gazing, posture, and gestures send forceful messages. In regard to nonverbal communication, eye gazing is one of the most strong forms that an individual can use. However, lack of mutual gazing occurs when we use video conferencing system. The displacement between locations of the eyes and a camera gets in the way of eye contact. The lack of eye gazing can give unapproachable and unpleasant feeling. In this paper, we propose an eye gazing correction for video conferencing. We use two cameras installed at the top and the bottom of the television. The captured two images are rendered with 2D warping at virtual position. We implement view morphing to the detected face, and synthesize the face and the warped image. The result shows that eye gazing is corrected and correctly preserved and the image was synthesized seamlessly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5C
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• pp.371-381
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• 2005

In this paper, we propose an advanced hardware architecture for the CAVLC entropy encoder/decoder engine for real time video compression. The CAVLC (Context-based Adaptive Variable Length Coding) is a lossless compression method in H.264/AVC and it has high compression efficiency but has computational complexity. The reference memory size is optimized using partitioned storing method and memory reuse method which are based on partiality of memory referencing. We choose the hardware architecture which has the most suitable one in several encoder/decoder architectures for the mobile devices and improve its performance using parallel processing. The proposed architecture has been verified by ARM-interfaced emulation board using Altera Excalibur and also synthesized on Samsung 0.18 um CMOS technology. The synthesis result shows that the encoder can process about 300 CIF frames/s at 150MHz and the decoder can process about 250 CIF frames/s at 140Mhz. The hardware architectures are being used as core modules when implementing a complete H.264/AVC video encoder/decoder chip for real-time multimedia application.

• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.1-8
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• 2021

In online meetings and classes using webcams, the chromakey technique is a very necessary part to produce content. We proposed a technology that enables background synthesis without using a cloth for chromakey. The proposed method consists of three steps: an HSI image conversion step, a step of detecting a region changed from a background, and a step of replacing the background region with a chromakey and applying it. In the input video, the block average image of each frame is calculated, and the difference between the block average image of the background image and the block average image of the input image is used to detect the change area. The developed chromakey effect technology uses a technique of acquiring a background image without an object from a single camera and extracting only an object by distinguishing the moving object and the background. The proposed method is not only capable of processing even if the background has a variety of colors, but also has the seamless processing of the boundary lines of objects.

• Journal of the Korea Computer Graphics Society
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• v.22 no.3
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• pp.89-99
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• 2016

One of the fundamental elements in developing mixed reality applications is to effectively analyze and apply the environmental lighting information to image synthesis. In particular, interactive applications require to process dynamically varying lighting sources in real-time, reflecting them properly in rendering results. Previous related works are not often appropriate for this because they are usually designed to synthesize photorealistic images, generating too many, often exponentially increasing, light sources or having too heavy a computational complexity. In this paper, we present a fast light source estimation technique that aims to search for primary light sources on the fly from a sequence of video images taken by a camera equipped with a fisheye lens. In contrast to previous methods, our technique can adust the number of found light sources approximately to the size that a user specifies. Thus, it can be effectively used in Phong-illumination-model-based direct illumination or soft shadow generation through light sampling over area lights.

• Archives of design research
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• v.18 no.2 s.60
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• pp.5-14
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• 2005

Graphic Design is being developed as a unique genre and widely applied to movie, TV broadcasting, music video, computer an, web design, animation, and game. Some university added motion graphics in their curriculum recently. However Motion Graphic has not been defined clearly and pedagogy of motion graphics was not studied enough. Motion Graphic is not merely moving picture. Its typical purpose and concept are evolving because of the diversified application. Meta-synthesis between media and hybrid development based on diverse approach and composite presentational methods are also changing Motion Graphic. Various technology such as photograph, analytical engine, hypermedia, multimedia, digital composite picture, network and interface should be studied to understand Motion Graphic. This study reviews the historic background of Motion Graphic mainly related to its advent. A fundamental definition of Motion Graphic including the space and time is suggested and the international trend is introduced. Future Motion Graphic and possible development was also predicted.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.2
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• pp.173-178
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• 2005

This paper focuses on the use of the virtual dialog system whose aim is to build more convenient living environments. In order to realize this, the main emphasis of the paper lies on the description of the multimedia signal processing on the basis of the technologies such as speech recognition, speech synthesis, video, or sensor signal processing. For essential modules of the dialog system, we incorporated the real-time speech recognizer based on HM-Net(Hidden Markov Network) as well as speech synthesis into the overall system. In addition, we adopted the real-time motion detector based on the changes of brightness in pixels, as well as the touch sensor that was used to start system. In experimental evaluation, the results showed that the proposed system was relatively easy to use for controlling electric appliances while sitting in a sofa, even though the performance of the system was not better than the simulation results owing to the noisy environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.409-419
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• 2013

Kinect released by Microsoft in November 2010 is a motion sensing camera in xbox360 and gives depth and color images. However, Kinect camera also generates holes and noise around object boundaries in the obtained images because it uses infrared pattern. Also, boundary flickering phenomenon occurs. Therefore, we propose a real-time virtual-view video synthesis algorithm which results in a high-quality virtual view by solving these problems. In the proposed algorithm, holes around the boundary are filled by using the joint bilateral filter. Color image is converted into intensity image and then flickering pixels are searched by analyzing the variation of intensity and depth images. Finally, boundary flickering phenomenon can be reduced by converting values of flickering pixels into the maximum pixel value of a previous depth image and virtual views are generated by applying 3D warping technique. Holes existing on regions that are not part of occlusion region are also filled with a center pixel value of the highest reliability block after the final block reliability is calculated by using a block based gradient searching algorithm with block reliability. The experimental results show that the proposed algorithm generated the virtual view image in real-time.

• Smart Media Journal
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• v.1 no.3
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• pp.29-35
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• 2012

A depth image-based rendering (DIBR) technique is one of the rendering processes of virtual views with a color image and the corresponding depth map. The most important issue of DIBR is that the virtual view has no information at newly exposed areas, so called dis-occlusion. In this paper, we propose an intermediate view generation algorithm using the Kinect depth camera that utilizes the infrared structured light. After we capture a color image and its corresponding depth map, we pre-process the depth map. The pre-processed depth map is warped to the virtual viewpoint and filtered by median filtering to reduce the truncation error. Then, the color image is back-projected to the virtual viewpoint using the warped depth map. In order to fill out the remaining holes caused by dis-occlusion, we perform a background-based image in-painting operation. Finally, we obtain the synthesized image without any dis-occlusion. From experimental results, we have shown that the proposed algorithm generated very natural images in real-time.