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Tokyo, Japan

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Shogen K.,B SAT | Kamei M.,Japan Telecommuinications Engineering and Consulting Service | Nakazawa S.,NHK STRL | Tanaka S.,NHK STRL
IEICE Transactions on Communications | Year: 2016

The indexes of the degradation of C=N, ΔT=T and I=N, which can be converted from one to another, are used to evaluate the impact of interference on the satellite link. However, it is not suitable to intuitively understand how these parameters degrade the quality of services. In this paper, we propose to evaluate the impact of interference on the performance of BSS (Broadcasting Satellite Services) in terms of the increase rate of the outage time caused by the rain attenuation. Some calculation results are given for the 12 GHz band BSS in Japan. Copyright © 2016 The Institute of Electronics, Information and Communication Engineers.


Park H.,NHK STRL | Oh J.,Realtime Visual Inc. | Seo B.-K.,17 Haengdang dong | Park J.-I.,17 Haengdang dong
Computer Animation and Virtual Worlds | Year: 2010

Model-based camera tracking is a technology that estimates a precise camera pose based on visual cues (e.g., feature points, edges) extracted from camera images given a 3D scene model and a rough camera pose. This paper proposes an automatic method for flexibly adjusting the confidence of visual cues in model-based camera tracking. The adjustment is based on the conditions of the target object/scene and the reliability of the initial or previous camera pose. Under uncontrolled or less-controlled working environments, the proposed objectadaptive tracking method works flexibly at 20 frames per second on an ultra mobile personal computer (UMPC) with an average tracking error within 3 pixels when the camera image resolution is 320 by 240 pixels. This capability enabled the proposed method to be successfully applied to a mobile augmented reality (AR) guidance system for a museum. Copyright © 2009 John Wiley & Sons, Ltd.


Yamashita T.,Ultrahiqh definilion TV Camera Systems | Kanazawa M.,NHK Science and Technology Research Laboratories STRL | Oyamada K.,NHK STRL | Hamasaki K.,NHK STRL | And 5 more authors.
SMPTE Motion Imaging Journal | Year: 2010

A report is present on the progress of research and development in the field of Super Hi-Vision (SHV), a UHDTV2 system as the highest class of UHDTV. The report covers the camera or display system and 22.2 multi-channel sound system, along with the delivery system, including the codec and transport technologies. It states that the rapid pace of technological progress has enabled researchers to develop a compact video and audio recording system and a prototype full 8K-resolution system. The transmission experiments using satellites and IP links and the standardization activity at ITU-R and SMPTE are also included in this report. The report reveals that research and development on SHV has focused on the system design and evaluation, prototype equipment, technological demonstrations, and standardization of the system parameters.


Liebetrau J.,Fraunhofer Institute for Digital Media Technology | Nagel F.,Fraunhofer Institute for Integrated Circuits | Zacharov N.,DELTA SenseLab | Watanabe K.,NHK STRL | And 4 more authors.
137th Audio Engineering Society Convention 2014 | Year: 2014

In audio quality evaluation, ITU-R BS.1534-1, commonly known as MUSHRA, is widely used for the subjective assessment of intermediate audio quality. Studies have identified limitations of the MUSHRA methodology.


Kusakabe T.,Ehime University | Kurakake T.,NHK Sendai Station | Oyamada K.,NHK STRL | Fujita Y.,Ehime University
ITE Transactions on Media Technology and Applications | Year: 2014

We previously proposed a time division multiplexing method for digital broadcasts over fiber-tothe- home. We evaluated the number of optical amplifiers, subscribers, and service areas with a simple star-type optical network model. Compared with the frequency division multiplexing methods used in conventional cable television systems, the number of optical amplifiers of our previously proposed method achieved less than 16 - 37% that of conventional methods or accommodated an increase in subscribers 2.9 - 6.1 times more than conventional methods even with an optical laser of inferior relative intensity noise (RIN). By analyzing a dominant factor for configuring a cost-effective distribution network, we found that it was valid to mitigate the requirement for optical power at a receiver and set a strict requirement for the RIN of an optical laser. © 2014 by ITE Transactions on Media Technology and Applications (MTA).


Uhm T.,Hanyang University | Park H.,NHK STRL | Park J.-I.,Hanyang University
Digest of Technical Papers - IEEE International Conference on Consumer Electronics | Year: 2011

There have been considerable endeavors for robustly tracking human (his/her whole body's or body parts') gestures for achieving na tural human-computer interaction but it is still a challenging problem in vision-based research area. In particular, trackings electively o ne's-of-interest (or his/her body parts') gestures, which is necessary in multi-user applications, is more difficult and has been less developed. In this paper, we propose a simple yet effective method for human-of-interest tracking, which combines a background subtraction method using difference keying, a skin region detection method in YCbCr color space, a region-of-interest detection method using the depth information from infrared images, and a region classification method based on a set of Haar-like features and A daboost learning algorithm. Based on the proposed method, we built a proof-of-concept system. The system proved to be able to provide natural frontal-view interaction with one of interest in real-time and robustly in a cluttered indoor and multi-user environments. We expect that our interaction system can provide a practical solution for natural interaction with digital in formation display systems and interactive game or education systems. ©2011 IEEE.


Uhm T.,Hanyang University | Park H.,NHK STRL | Lee M.-H.,Hanyang University | Park J.-I.,Hanyang University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

There has been considerable interest in immersive and realistic virtual environment system and how to improve human and computer interaction has been a main challenge. For vision-based human-computer interaction, extraction of user region from camera images is an essential part. In this paper, we propose a background subtraction method that segments dynamic projected background in a rear-projection-based virtual environment system. In the projector-camera system, the projected background is inherently known by the projector input images although its appearance is changed by the geometric and radiometric transformation between projector and camera. Therefore, we can compute the expected background location and appearance based on geometric and radiometric calibration of projector-camera system and thus separate user region from dynamic projected background by simple subtraction between camera images and the computed background. Experimental results are given for verifying the usefulness of the proposed method. © 2010 Copyright SPIE - The International Society for Optical Engineering.


Hisatomi K.,NHK STRL | Hisatomi K.,University of Tokyo | Ikeya K.,NHK STRL | Katayama M.,NHK STRL | And 2 more authors.
ACM International Conference Proceeding Series | Year: 2013

This paper proposes a robust depth-estimation method that projects infrared dot-patterns in order to estimate depth maps of a low-texture dynamic scene. Two infrared cameras are utilized to observe the projected infrared patterns, and the depth maps are estimated by stereo matching of the patterns. The stereo matching makes use of a cost volume with a cross-based local multipoint filter (CLMF) which is an edge-preserving smoothing filter using adaptive kernels. The adaptive kernel is a window that is adaptively decided by selecting pixels of similar color. In this paper, CLMF is extended (st-CLMF) beyond the spatial dimension to the temporal dimension. The proposed method is evaluated using scenes including low-texture regions. The experimental results show that st-CMLF can perform accurate depth estimations. © 2013 ACM.


Uhm T.,Hanyang University | Park H.,NHK STRL | Seo D.,Hanyang University | Park J.-I.,Hanyang University
Proceedings - IEEE Virtual Reality | Year: 2010

Human, especially human-of-interest, detection and tracking is a necessary part for immersive and realistic human-computer interaction. Thus, we propose an intelligent multi-vision-based human detection and tracking system that consists of a visible camera, an infrared camera, a dynamic infrared lighting system, and a cold mirror. The system segments a human region of interest and tracks his/her motion. Experimental results are given for verifying the usefulness of the proposed method. ©2010 IEEE.

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