Hybrid 3DTV Research Articles

Development of 3DTV Emission Multiplexer and Reception-Signal Status Analyzer for ATSC 8-VSB & MDTV Hybrid 3DTV Services

ABSTRACT This paper describes the development of a real-time three-dimensional television (3DTV) emission multiplexer and reception – signal status analyzing system for Advanced Television Systems Committee 8-vestigial side-band (ATSC 8-VSB) & mobile digital television (MDTV) hybrid 3DTV service. Recently, this system has been adopted as a standard (ATSC A/104 Part 5) of the terrestrial 3DTV broadcasting service under the name of service compatible-main and mobile hybrid (SC-MMH) 3DTV. Compared to the existing ATSC MDTV 2D systems, the SC-MMH 3DTV system requires 8-VSB (left-eye images) and MDTV (right-eye images) frame synchronization. 3DTV shall receive both 8-VSB and MDTV signals simultaneously. For a seamless SC-MMH 3DTV service within these service constraints, broadcasters should deploy transmitters and measuring services over the coverage area. In this paper, we introduce the implementation of SC-MMH 3DTV emission multiplexer and reception-signal status analyzer to configure the transmitter and signal measurements more efficiently. The options of the proposed system are verified by the SC-MMH 3DTV field test in a real terrestrial broadcasting environment.

Design of Synchronization and T-STD Model for 3DTV Service over Hybrid Networks

The objective of digital broadcasting has evolved from providing a plain video service to offering a realistic visual experience. Technologies such as 3DTV and UHDTV have been suggested to achieve this new objective by providing an immersive and stereoscopic visual experience. However, owing to the high bandwidth requirements of such services, the broadcasting industry has faced a challenge to find a new transport mechanism for overcoming the bandwidth limitation. The standardization organizations, the Advanced Television Systems Committee, Digital Video Broadcasting, and Telecommunications Technology Association, have been working on the integration of broadcasting and a broadband network (IP) to resolve the bandwidth issue of realistic video services. This paper introduces a frame-level timeline synchronization and transport system target decoder model for providing a stable 3DTV service over a hybrid network. The experimental results indicate that the proposed technologies can be successfully adopted as a reference model in a broadcast-broadband hybrid 3DTV service and other IP-associated hybrid broadcasting services.

A method to reduce the complexity of conditional replenishment algorithm for hybrid 3DTV with mixed resolution

SC-MMH (Service Compatible 3DTV using Main and Mobile Hybrid) is a kind of hybrid 3DTV system where the resolutions of stereoscopic views are not identical and has become one of ATSC standards for terrestrial 3DTV. And CRA (Conditional Replenishment Algorithm) has been proposed to enhance the visual quality of this asymmetrical hybrid 3DTV with mixed resolution. CRA uses a variable-sized square block as a PU (Processing Unit) and the quad-tree is employed to represent the overall hierarchical structure. The largest and smallest sizes of PU of quad-tree affect the RD (Rate-Distortion) performance as well as the computational complexity of CRA. In this paper, we examine the effect of quad-tree levels on the BD-PSNR and the processing time. And we suggest the proper set of top and bottom levels which reduces the complexity of CRA with a negligible degradation of quality. Simulation for the stereoscopic sequences of HD resolution showed that the processing time of CRA can be considerably reduced to 70 % but the decrease of BD-PSNR is only 0.02 dB by employing of the combination of (7, 2) levels instead of conventional combination of (8, 0) levels. And the processing time could be more reduced to 60 % for UHD sequences when we used the combination of (7, 3) levels.

Quality Enhancement for Hybrid 3DTV with Mixed Resolution Using Conditional Replenishment Algorithm

This paper proposes a conditional replenishment algorithm (CRA) to improve the visual quality (where spatial resolutions of the left and right views are mismatched) of a hybrid stereoscopic 3DTV that is based on the ATSC-M/H standard. So as to generate an enhanced view, the CRA is to choose the better substitute among a disparity-compensated view with high quality and a simply interpolated view. The CRA generates a disparity map that includes modes and disparity vectors as additional information. It also employs a quad-tree structure with variable block size by considering the spatial correlation of disparity vectors. In addition, it takes advantage of the disparity map used in a previous frame to keep the amount of additional information as small as possible. The simulation results show that the proposed CRA can successfully improve the peak signal-to-noise ratio of a poor-quality view and consequently have a positive effect on the subjective quality of the resulting 3D view.

Integration of Multisensorial Stimuli and Multimodal Interaction in a Hybrid 3DTV System

This article proposes the integration of multisensorial stimuli and multimodal interaction components into a sports multimedia asset under two dimensions: immersion and interaction . The first dimension comprises a binaural audio system and a set of sensory effects synchronized with the audiovisual content, whereas the second explores interaction through the insertion of interactive 3D objects into the main screen and on-demand presentation of additional information in a second touchscreen. We present an end-to-end solution integrating these components into a hybrid (internet-broadcast) television system using current 3DTV standards. Results from an experimental study analyzing the perceived quality of these stimuli and their influence on the Quality of Experience are presented.

ATSC-M/H 기반의 융합형 3DTV를 위한 양안시차 고속 추정 알고리즘

3D 방송시스템에 대한 다양한 연구 가운데 ATSC-M/H 기반의 융합형 3DTV 방식은 HD 화질의 좌영상과 모바일 화질의 우영상을 결합하는 서비스 호환 3DTV 시스템으로서 이 방식에서는 좌우 영상 사이에 상대적인 화질 차이가 존재하며 이를 해결하기 위해 조건부 대체 알고리즘(Conditional Replenishment Algorithm)이 제안되었다. 조건부 대체 알고리즘에서는 좌우영상 사이의 양안시차 벡터를 추정하고 양안시차 보상된 HD 좌영상과 단순 확장된 모바일 우영상을 선택적으로 사용함으로써 우영상의 화질을 개선한다. 그러나 이 알고리즘은 여러 계층의 양안시차를 추정하는 과정에서 매우 많은 계산이 필요하기 때문에 이를 실제적으로 구현하기 위해서는 고속 알고리즘의 개발이 요구된다. 본 논문에서는 양안시차 벡터의 특성을 고려하여 전역 탐색 대신에 SDSP(Small Diamond Search Pattern) 탐색 방법을 사용하고 탐색의 초기위치를 예측하는 방법을 제안하며 특정 조건 하에서 양안시차 벡터 추정을 생략하는 조기종료 모드를 함께 적용함으로써 복원 영상의 화질을 유지하면서도 조건부 대체 알고리즘의 속도를 향상시키는 기법을 제안하고 모의실험을 통해 이의 성능을 검증하였다. ATSC-M/H based hybrid 3DTV, which is one of the service compatible 3DTV system, has considerable quality gap between the left and right views. And CRA(Conditional Replenishment Algorithm) has been proposed to deal with the issue of resolution mismatch and improve the visual quality. In CRA, the disparity vectors of stereoscopic images are estimated. The disparity compensated left view and simply enlarged right view are compared and conditionally selected for generating the enhanced right view. In order to implement CRA, a fast algorithm is strongly required because the disparity vectors need to be obtained at every layer and the complexity of CRA is quite high. In this paper, we adopted SDSP(Small Diamond Search Pattern) instead of full search and predicted the initial position of search pattern by examining the spatio-temporal correlation of disparity vectors and also suggested the SKIP mode to limit the number of processing units. The computer simulation showed that the proposed fast algorithm could greatly reduce the processing time while minimizing the quality degradation of reconstructed right view.

혼합 해상도 양안식 영상에 대한 주관적 화질평가를 통한 고정 및 이동 융합형 3DTV 서비스의 품질 검증

양안식 3D 비디오의 효율적인 압축을 위해 다양한 기술들이 연구되었으며, 그 중 좌우영상으로 상이한 해상도의 영상을 사용하는 방식은 인간의 시각 시스템이 혼합 해상도의 양안식 영상을 높은 쪽 영상의 품질에 가깝게 인지하는 특성을 이용한 대표적인 비트레이트 절감 방식이다. 그러나 혼합 해상도 양안식 영상에서 좌우안 영상 해상도 차이가 일정 범위 이상일 경우 3D 영상의 품질 저하가 발생한다. 이에 다양한 연구에서 혼합 해상도 양안식 영상의 좌우해상도 차이에 따른 화질 저하 정도를 측정하려는 시도가 이루어졌으나, 기존 연구에서는 시청거리를 고려하지 않고 단순 좌우 영상의 크기만을 고려하여 실험하였으며 이에 각 연구별로 상이한 실험 결과가 도출되었다. 본 연구에서는 인간의 시각 시스템을 고려하여 최적 시청거리를 계산하고, 이에 기반하여 좌우영상 비율 별 주관적 화질평가를 수행하였다. 또한 실험 결과 분석을 통해 혼합 해상도 영상 기반의 고정 및 이동 융합형 3DTV 기술이 고품질 3D 서비스를 제공할 수 있음을 보인다. Various techniques have been developed for efficient compression of stereoscopic 3D videos. Mixed-resolution based approach is one representative bit-rate saving method based on the characteristics of human visual system that the mixed-resolution stereoscopic videos are perceived close to the higher resolution. However, when the difference between the left and right image resolutions is bigger than a certain threshold level, it causes the perceived quality degradation of the 3D images. Subsequently, several researches tried to find the correlation between the difference in resolution and the level of the perceived quality degradation, but they conducted the experiments just considering the difference in resolution without considering the viewing distances, so thereby different results were retrieved from test to test. In this work, we calculated the optimal viewing distance based on the human visual system, and conducted the subjective tests with the calculated viewing distance. With the results, we demonstrate that the fixed and mobile hybrid 3DTV, which is based on mixed-resolution stereoscopic images, can provide the high quality 3D services.

A 3DTV Broadcasting Scheme for High-Quality Stereoscopic Content Over a Hybrid Network

Various methods are used to provide three-dimensional television (3DTV) services over a terrestrial broadcasting network. However, these services cannot provide high-quality 3D content to consumers. It is because current terrestrial broadcast networks are allocated with limited bandwidths to transmit 3D content while 3D content requires larger bandwidth compared to that of 2D content. To overcome this limitation, this paper proposes a hybrid 3DTV broadcasting system, which utilizes both a terrestrial broadcast network and a broadband network. In the proposed system, two elementary streams of left and right views for a stereoscopic video service are transmitted over a terrestrial broadcasting network and a broadband network, respectively. In addition, the proposed system suggests a new mechanism for synchronization between these two elementary streams. The proposed scheme can provide high-quality 3DTV service regardless of bandwidth of the terrestrial broadcast network while maintaining backward compatibility with a 2D DTV broadcasting service.