• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.10C
• /
• pp.982-989
• /
• 2007

In this paper, we propose a 3DTV system that considers user's view point and display environment. The proposed system consists of 3 parts - multi-view encoder/decoder, face-tracker, and 2D/3D converter. The proposed system try to encode multi-view sequence and decode it in accordance with the user's view point and it also gives a stereopsis to the multi-view image by using of 2D/3D conversion which converts decoded two-dimensional(2D) image to three-dimensional(3D) image. Experimental results shows that we are able to correctly reconstruct a stereoscopic view that is exactly corresponding to user's view point.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2011.11a
• /
• pp.240-241
• /
• 2011

자연스러운 3D 실감영상을 감상하기 위해서는 많은 시점의 영상이 필요하며 과거 스테레오 디스플레이 장치로부터 최근 그 시점 수가 크게 늘어난 디스플레이 장치로 기술 발전이 이뤄지고 있으며 이에 따라 다시점 콘텐츠를 생성하기 위한 다양한 기술이 개발되어 있다. 다시점 콘텐츠를 생성하기 위하여 ToF 카메라 및 적외선 패턴을 이용한 방법이 주로 이용되고 있으며 이를 활용한 다시점 콘텐츠 생성을 하는 시도가 이뤄지고 있다. ToF 카메라는 PMD사의 제품 및 SwissRanger 사의 제품이 대표적이며 적외선 패턴을 이용한 방식은 MS사의 Kinect가 대표적이며 본 제품들을 활용한 기술 비교를 통하여 다시점 콘텐츠 생성의 결과 및 이를 비교한 장단점을 구분하였다. PMD사의 ToF 카메라는 두 개 이상의 광원을 사용하여 Depth 추출시에 Hole 영역의 크기가 작으나 ToF 영상의 해상도가 매우 작아 고화질의 콘텐츠를 생성하기 위하여 별도의 영상처리 알고리즘이 요구되었다. 반면 MS사의 Kinect는 Depth 영상의 해상도가 상대적으로 커서 영상처리 알고리즘의 복잡도가 작아지나 Depth 추출을 위한 카메라와 RGB 카메라의 위치가 공간적으로 떨어져 있어 이를 보정하기 위한 알고리즘이 요구되며 다시점 변환시 화질에 있어 상대적으로 떨어지는 것으로 나타났다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2011.11a
• /
• pp.270-272
• /
• 2011

다시점 비디오는 사용자들에게 자유로운 시점 선택 및 넓은 시점에서의 입체감을 제공하지만, 시점의 증가에 따른 데이터 량의 증가가 불가피하다. 이에 따라 최근 MPEG 에서는 재생되는 시점 수 보다 적은 수의 다시점 비디오와 그에 대응하는 깊이 영상 및 관련 파라미터를 메타데이터 형태로 제공하는 다시점 및 깊이 영상 부호화(MVD: Multiview plus Depth)에 대한 표준화를 진행하고 있다. 본 논문은 MVD 가 방송망에서 서비스되는 시나리오를 가정하여 다시점 비디오와 그에 대응하는 깊이 영상을 MPEG-2 TS(Transport Stream)로 전송하기 위한 기법을 제시한다. 제안한 기법은 기존의 단일 영상 및 깊이 영상을 전송하기 위한 부가비디오스트림 서술자(Auxiliary Video Stream Descriptor) 및 MPEG-C Part 3 표준을 확장하여 다시점 비디오와 그에 대응하는 깊이 영상간의 매핑 정보 및 각 시점의 깊이 파라미터를 제공할 수 있다.

• 한국HCI학회:학술대회논문집
• /
• 2009.02a
• /
• pp.620-624
• /
• 2009

In this paper, we present a new camera system combining a high-quality 3-D scanner and hybrid camera system to generate a multiview video-plus-depth. In order to get the 3-D video using the hybrid camera system and 3-D scanner, we first obtain depth information for background region from the 3-D scanner. Then, we get the depth map for foreground area from the hybrid camera system. Initial depths of each view image are estimated by performing 3-D warping with the depth information. Thereafter, multiview depth estimation using the initial depths is carried out to get each view initial disparity map. We correct the initial disparity map using a belief propagation algorithm so that we can generate the high-quality multiview disparity map. Finally, we refine depths of the foreground boundary using extracted edge information. Experimental results show that the proposed depth maps generation method produces a 3-D video with more accurate multiview depths and supports more natural 3-D views than the previous works.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.46 no.1
• /
• pp.41-48
• /
• 2009

This Paper introduces representation and coding schemes of multiview texture and depth data for complex three-dimensional scenes. We represent input color and depth images using compressed texture and depth map pairs. The proposed X-codec encodes them further to increase compression ratio in a near-lossless way. Our system resolves two problems. First, rendering time and output visual quality depend on input image resolutions rather than scene complexity since a depth image-based rendering techniques is used. Second, the random access problem of conventional image-based rendering could be effectively solved using our image block-based compression schemes. From experimental results, the proposed approach is useful to graphics applications because it provides multiview rendering, selective decoding, and scene manipulation functionalities.

• Journal of KIISE
• /
• v.41 no.11
• /
• pp.900-910
• /
• 2014

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. The computational complexity of multi view video coding increases in proportion to the number of cameras. To reduce computational complexity and maintain the image quality, improved prediction structure and motion estimation method is proposed in this paper. The proposed prediction structure exploits an average distance between the current picture and its reference pictures. The proposed prediction structure divides every GOP into several groups to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. And the proposed motion estimation method uses a hierarchical search strategy. This strategy method consists of modified diamond search pattern, progressive diamond search pattern and modified raster search pattern. Experiment results show that the complexity reduction of the proposed prediction structure and motion estimation method over JMVC (Joint Multiview Video Coding) reference model using hierarchical B pictures of Fraunhofer-HHI and TZ search method can be up to 40~70% while maintaining similar video quality and bit rates.

• Journal of Broadcast Engineering
• /
• v.11 no.4 s.33
• /
• pp.420-430
• /
• 2006

In this paper, we propose a flexible GGOP prediction structure to improve coding efficiency for multi-view video coding. In general, reference software used for MVC uses the fixed GGOP prediction structure. However, the performance of MVC depends on the base view and numbers of B-pictures between I-picture(or P-picture) and P-picture. In order to implement the flexible GGOP prediction structure, the location of base view is decided according to the global disparities among the adjacent sequences. Numbers of B-pictures between I-picture(or P-picture) and P-picture are decided by camera arrangement such as the baseline distance among the cameras. The proposed method shows better result than the reference software of MVC. The proposed prediction structure shows considerable reduction of coded bits by 7.1%.

• Journal of Korea Multimedia Society
• /
• v.15 no.9
• /
• pp.1093-1101
• /
• 2012

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. Multi-view video coding exploits inter-view correlations among pictures of neighboring views and temporal correlations among pictures of the same view. Multi-view video coding which uses many cameras requires a method to reduce the computational complexity. In this paper, we proposed an efficient prediction structure to improve performance of multi-view video coding. The proposed prediction structure exploits an average distance between the current picture and its reference pictures. The proposed prediction structure divides every GOP into several small groups to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. Experimental results show that the proposed prediction structure shows good performance in image quality and bit-rates. When compared to the performance of hierarchical B pictures of Fraunhofer-HHI, the proposed prediction structure achieved 0.07~0.13 (dB) of PSNR gain and was down by 6.5(Kbps) in bitrate.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.8
• /
• pp.1704-1713
• /
• 2011

This paper proposes a method to generate multiview images which use a synthesized image consisting of layered objects. The camera system which consists of a depth camera and a RGB camera is used in capturing objects and extracts 3-dimensional information. Considering the position and distance of the synthesizing image, the objects are synthesized into a layered image. The synthesized image is spaned to multiview images by using multiview generation tools. In this paper, we synthesized two images which consist of objects and human and the multiview images which have 37 view points were generated by using the synthesized images.

• Journal of Broadcast Engineering
• /
• v.15 no.4
• /
• pp.591-599
• /
• 2010

In this paper, we propose a disparity-adaptive filtering method to reduce view-aliasing and inter-perspective aliasing on auto-multiscopic 3D display. View aliasing by the subsampled multi-view images could happen if the resolution of an auto-multiscopic monitor is lower than that of the original multi-view images. Furthermore, multi-view images on auto-multiscopic monitor usually cause eye strain and fatigue because of inter-perspective aliasing by discontinuity that exists between viewpoints. The greater disparity value becomes, the stronger these types of aliasing could be. Thus, we design a lowpass filter whose cut-off frequency is determined adaptively to the number of intermediate reconstructed views and their disparity's strength. Though experimental results, we show that the proposed filtering algorithm could reduce the aliasing effect very efficiently by using DSCQS (double stimulus continuous quality scale method).