• Title/Summary/Keyword: depth map

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Effects of Depth Map Quantization for Computer-Generated Multiview Images using Depth Image-Based Rendering

  • Kim, Min-Young;Cho, Yong-Joo;Choo, Hyon-Gon;Kim, Jin-Woong;Park, Kyoung-Shin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.11
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    • pp.2175-2190
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    • 2011
  • This paper presents the effects of depth map quantization for multiview intermediate image generation using depth image-based rendering (DIBR). DIBR synthesizes multiple virtual views of a 3D scene from a 2D image and its associated depth map. However, it needs precise depth information in order to generate reliable and accurate intermediate view images for use in multiview 3D display systems. Previous work has extensively studied the pre-processing of the depth map, but little is known about depth map quantization. In this paper, we conduct an experiment to estimate the depth map quantization that affords acceptable image quality to generate DIBR-based multiview intermediate images. The experiment uses computer-generated 3D scenes, in which the multiview images captured directly from the scene are compared to the multiview intermediate images constructed by DIBR with a number of quantized depth maps. The results showed that there was no significant effect on depth map quantization from 16-bit to 7-bit (and more specifically 96-scale) on DIBR. Hence, a depth map above 7-bit is needed to maintain sufficient image quality for a DIBR-based multiview 3D system.

A New Copyright Protection Scheme for Depth Map in 3D Video

  • Li, Zhaotian;Zhu, Yuesheng;Luo, Guibo;Guo, Biao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.7
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    • pp.3558-3577
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    • 2017
  • In 2D-to-3D video conversion process, the virtual left and right view can be generated from 2D video and its corresponding depth map by depth image based rendering (DIBR). The depth map plays an important role in conversion system, so the copyright protection for depth map is necessary. However, the provided virtual views may be distributed illegally and the depth map does not directly expose to viewers. In previous works, the copyright information embedded into the depth map cannot be extracted from virtual views after the DIBR process. In this paper, a new copyright protection scheme for the depth map is proposed, in which the copyright information can be detected from the virtual views even without the depth map. The experimental results have shown that the proposed method has a good robustness against JPEG attacks, filtering and noise.

Auto-Covariance Analysis for Depth Map Coding

  • Liu, Lei;Zhao, Yao;Lin, Chunyu;Bai, Huihui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.9
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    • pp.3146-3158
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    • 2014
  • Efficient depth map coding is very crucial to the multi-view plus depth (MVD) format of 3-D video representation, as the quality of the synthesized virtual views highly depends on the accuracy of the depth map. Depth map contains smooth area within an object but distinct boundary, and these boundary areas affect the visual quality of synthesized views significantly. In this paper, we characterize the depth map by an auto-covariance analysis to show the locally anisotropic features of depth map. According to the characterization analysis, we propose an efficient depth map coding scheme, in which the directional discrete cosine transforms (DDCT) is adopted to substitute the conventional 2-D DCT to preserve the boundary information and thereby increase the quality of synthesized view. Experimental results show that the proposed scheme achieves better performance than that of conventional DCT with respect to the bitrate savings and rendering quality.

Depth Map Refinement using Segment Plane Estimation (세그멘트 평면 추정을 이용한 깊이 지도 개선)

  • Jung, Woo-Kyung;Han, Jong-Ki
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.286-287
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    • 2020
  • Depth map is the most common way of expressing 3D space in immersive media. In this paper, we propose a post-processing method to improve the quality of depth map. In proposed method, a depth map is divided into segments, and the plane of each segment estimated using RANSAC. In order to increase the accuracy of the RANSAC process, we apply matching reliability of each pixel in depth map as a weighting factor.

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Propriety analysis of Depth-Map production methods For Depth-Map based on 20 to 3D Conversion - the Last Bladesman (2D to 3D Conversion에서 Depth-Map 기반 제작 사례연구 - '명장 관우' 제작 중심으로 -)

  • Kim, Hyo In;Kim, Hyung Woo
    • Smart Media Journal
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    • v.3 no.1
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    • pp.52-62
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    • 2014
  • Prevalence of common three-dimensional display progresses, increasing the demand for three-dimensional content. Starting from the year 2010 to meet increasing 2D to 3D conversion is insufficient to meet demand content was presented as an alternative. But, Convert 2D to 3D stereo effect only emphasizes content production as a three-dimensional visual fatigue and the degradation of the Quality problems are pointed out. In this study, opened in 2011 'Scenes Guan', the 13 selected Scene is made of the three-dimensional transform the content and the Quality of the transformation applied to the Depth-Map is a visual representation of three-dimensional fatigue and, the adequacy of whether the expert has group interviews and surveys were conducted. Many of the changes are applied to the motion picture of the three-dimensional configurations of Depth-Map conversion technology used in many ways before and after the analysis of the relationship of cascade configurations to create a depth map to the stage. Experiments, presented in this study is a three-dimensional configuration of Depth-Map transformation can lower the production of a three-dimensional visual fatigue and improve the results obtained for a reasonable place was more than half of the experiment accepted the expert group to show a positive reaction were. The results of this study with a rapid movement to convert 2D images into 3D images of applying Depth-map configuration cascade manner to reduce the visual fatigue, to increase the efficiency, and has a three-dimensional perception is the result derived.

A Study for Depth-map Generation using Vanishing Point (소실점을 이용한 Depth-map 생성에 관한 연구)

  • Kim, Jong-Chan;Ban, Kyeong-Jin;Kim, Chee-Yong
    • Journal of Korea Multimedia Society
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    • v.14 no.2
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    • pp.329-338
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    • 2011
  • Recent augmentation reality demands more realistic multimedia data with the mixture of various media. High-technology for multimedia data which combines existing media data with various media such as audio and video dominates entire media industries. In particular, there is a growing need to serve augmentation reality, 3-dimensional contents and realtime interaction system development which are communication method and visualization tool in Internet. The existing services do not correspond to generate depth value for 3-dimensional space structure recovery which is to form solidity in existing contents. Therefore, it requires research for effective depth-map generation using 2-dimensional video. Complementing shortcomings of existing depth-map generation method using 2-dimensional video, this paper proposes an enhanced depth-map generation method that defines the depth direction in regard to loss location in a video in which none of existing algorithms has defined.

Depth-Map Generation using Fusion of Foreground Depth Map and Background Depth Map (전경 깊이 지도와 배경 깊이 지도의 결합을 이용한 깊이 지도 생성)

  • Kim, Jin-Hyun;Baek, Yeul-Min;Kim, Whoi-Yul
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.275-278
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    • 2012
  • 본 논문에서 2D-3D 자동 영상 변환을 위하여 2D 상으로부터 깊이 지도(depth map)을 생성하는 방법을 제안한다. 제안하는 방법은 보다 정확한 깊이 지도 생성을 위해 영상의 전경 깊이 지도(foreground depth map)와 배경 깊이 지도(background depth map)를 각각 생성 한 후 결합함으로써 보다 정확한 깊이 지도를 생성한다. 먼저, 전경 깊이 지도를 생성하기 위해서 라플라시안 피라미드(laplacian pyramid)를 이용하여 포커스/디포커스 깊이 지도(focus/defocus depth map)를 생성한다. 그리고 블록정합(block matching)을 통해 획득한 움직임 시차(motion parallax)를 이용하여 움직임 시차 깊이 지도를 생성한다. 포커스/디포커스 깊이 지도는 평탄영역(homogeneous region)에서 깊이 정보를 추출하지 못하고, 움직임 시차 깊이 지도는 움직임 시차가 발생하지 않는 영상에서 깊이 정보를 추출하지 못한다. 이들 깊이 지도를 결합함으로써 각 깊이 지도가 가지는 문제점을 해결하였다. 선형 원근감(linear perspective)와 선 추적(line tracing) 방법을 적용하여 배경깊이 지도를 생성한다. 이렇게 생성된 전경 깊이 지도와 배경 깊이 지도를 결합하여 보다 정확한 깊이 지도를 생성한다. 실험 결과, 제안하는 방법은 기존의 방법들에 비해 더 정확한 깊이 지도를 생성하는 것을 확인할 수 있었다.

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Depth Map Coding Using Histogram-Based Segmentation and Depth Range Updating

  • Lin, Chunyu;Zhao, Yao;Xiao, Jimin;Tillo, Tammam
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.3
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    • pp.1121-1139
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    • 2015
  • In texture-plus-depth format, depth map compression is an important task. Different from normal texture images, depth maps have less texture information, while contain many homogeneous regions separated by sharp edges. This feature will be employed to form an efficient depth map coding scheme in this paper. Firstly, the histogram of the depth map will be analyzed to find an appropriate threshold that segments the depth map into the foreground and background regions, allowing the edge between these two kinds of regions to be obtained. Secondly, the two regions will be encoded through rate distortion optimization with a shape adaptive wavelet transform, while the edges are lossless encoded with JBIG2. Finally, a depth-updating algorithm based on the threshold and the depth range is applied to enhance the quality of the decoded depth maps. Experimental results demonstrate the effective performance on both the depth map quality and the synthesized view quality.

Implementing a Depth Map Generation Algorithm by Convolutional Neural Network (깊이맵 생성 알고리즘의 합성곱 신경망 구현)

  • Lee, Seungsoo;Kim, Hong Jin;Kim, Manbae
    • Journal of Broadcast Engineering
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    • v.23 no.1
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    • pp.3-10
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    • 2018
  • Depth map has been utilized in a varity of fields. Recently research on generating depth map by artificial neural network (ANN) has gained much interest. This paper validates the feasibility of implementing the ready-made depth map generation by convolutional neural network (CNN). First, for a given image, a depth map is generated by the weighted average of a saliency map as well as a motion history image. Then CNN network is trained by test images and depth maps. The objective and subjective experiments are performed on the CNN and showed that the CNN can replace the ready-made depth generation method.

Fast Intra Mode Decision Algorithm for Depth Map Coding using Texture Information in 3D-AVC (3D-AVC에서 색상 영상 정보를 이용한 깊이 영상의 빠른 화면 내 예측 모드 결정 기법)

  • Kang, Jinmi;Chung, Kidong
    • Journal of Korea Multimedia Society
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    • v.18 no.2
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    • pp.149-157
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    • 2015
  • The 3D-AVC standard aims at improving coding efficiency by applying new techniques for utilizing intra, inter and view predictions. 3D video scenes are rendered with existing texture video and additional depth map. The depth map comes at the expense of increased computational complexity of the encoding process. For real-time applications, reducing the complexity of 3D-AVC is very important. In this paper, we present a fast intra mode decision algorithm to reduce the complexity burden in the 3D video system. The proposed algorithm uses similarity between texture video and depth map. The best intra prediction mode of the depth map is similar to that of the corresponding texture video. The early decision algorithm can be made on the intra prediction of depth map coding by using the coded intra mode of texture video. Adaptive threshold for early termination is also proposed. Experimental results show that the proposed algorithm saves the encoding time on average 29.7% without any significant loss in terms of the bit rate or PSNR value.