• Title/Summary/Keyword: Stereoscopic algorithm

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A New Watermarking Algorithm for Copyright Protection of Stereoscopic Image (스테레오 영상의 소유권 보호를 위한 워터마킹 기법)

  • Seo, Young-Ho;Koo, Ja-Myung;Kim, Dong-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.8
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    • pp.1663-1674
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    • 2012
  • In this paper, we propose a new watermarking technique for copyright protection of stereo image. The proposed technique embeds watermark to the region which corresponds to occlusion of the disparity map to be extracted by the proposed stereo matching and the frequency coefficient with the appropriate value. We use discrete wavelet transform for frequency transform tool. The proposed algorithm consists of stereo matching, watermark rearrange, mark space selection, and watermark embedding/extracting. We tested the experiment about 4 stereo images which are from Middlebury site. We embedded the watermark to 4 stereo images and extracted it from the images after attacks. We also visually analyzed the watermark embedding images in 3D TV environment.

Implementation of Object-based Multiview 3D Display Using Adaptive Disparity-based Segmentation

  • Park, Jae-Sung;Kim, Seung-Cheol;Bae, Kyung-Hoon;Kim, Eun-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1615-1618
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    • 2005
  • In this paper, implementation of object-based multiview 3D display using object segmentation and adaptive disparity estimation is proposed and its performance is analyzed by comparison to that of the conventional disparity estimation algorithms. In the proposed algorithm, firstly we can get segmented objects by region growing from input stereoscopic image pair and then, in order to effectively synthesize the intermediate view the matching window size is selected according to the extracted feature value of the input stereo image pair. Also, the matching window size for the intermediate view reconstruction (IVR) is adaptively selected in accordance with the magnitude of the extracted feature value from the input stereo image pair. In addition, some experimental results on the IVR using the proposed algorithm is also discussed and compared with that of the conventional algorithms.

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Stereo Image Coding Using Zerotree (제로트리 기법을 이용한 스테레오 영상 부호화)

  • Bae, Jin-Woo;Shin, Choel;Yoo, Ji-Sang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.12A
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    • pp.2092-2099
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    • 2001
  • In the three-dimensional image system using stereoscopic images, efficient coding schemes which can get rid of redundancy between the left and right images are usually used. In this paper, we propose an efficient coding method by using relationship between a reference image and residual image. In the proposed algorithm, zero-tree method which guaranty a good quality in low bit rate is used for encoding the residual image. Zero-tree algorithm gives good coding performance, but it has computational complexity so that we used ADLS method to reduce time for the disparity estimation. Using the wavelet based zero-tree method, it is shown that high quality of image in the limited band-width can be preserved through computer simulation.

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A Method for Determining the Coiling Ratio and Classifying Species of Fossil Planktonic Foraminifera Using Digital Image Analysis (디지털 이미지 분석을 이용한 부유성 유공충 화석의 권각 방향과 종 분류 결정법)

  • Shin, Sang-Hun
    • Journal of the Korean earth science society
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    • v.25 no.8
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    • pp.799-811
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    • 2004
  • In this one species of planktonic foraminifers, Neogloboquadrina pachyderma, which has been collected from the sediments cores in the northeast Pacific ODP sites, was computerized through using digitalized images. The foraminiferal communities were analyzed, and the coiling direction of the N. pachyderma was determined by using computer progamming technology. In this way by appling algorithm-based method of reading, the tasks of sorting and analyzing the foraminiferal indiniduals and communities can be performad and high speed on a very large amount of specimens collected. It is found that the study had 90% accordance with the result of stereoscopic observation. This result suggested that digital image analysis could be successfully adopted in the field of micropaleontology.

A New Stereo Matching Algorithm based on Variable Windows using Frequency Information in DWT Domain (DWT 영역에서의 주파수 정보를 활용한 가변 윈도우 기반의 스테레오 정합 알고리즘)

  • Seo, Young-Ho;Koo, Ja-Myung;Kim, Dong-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.7
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    • pp.1437-1446
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    • 2012
  • In this paper we propose a new stereo matching algorithm which is suitable for application to obtain depth information with high-speed in stereoscopic camera environment. For satisfying these condition we propose a new adaptive stereo matching technique using frequency information in discrete wavelet (DWT) domain and variable matching window. The size of the matching window is selected by analysis of the local property of the image in spatial domain and the feature and scaling factor of the matching window is selected by the frequency property in the frequency domain. For using frequency information we use local DWT and global DWT. We identified that the proposed technique has better peak noise to signal ratio (PSNR) than the fixed matching techniques with similar complexity.

Collision detection algorithm by using mesh grouping (메쉬 그룹화를 이용한 충돌 검출 알고리즘)

  • Park, Jong-Seop;Jang, Tae-Jeong
    • Journal of Digital Contents Society
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    • v.19 no.1
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    • pp.199-204
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    • 2018
  • In this paper, we propose a fast collision detection method for interacting with objects in virtual space. First, in the mesh grouping step, the entire space is divided into small spaces of a predetermined size, and the positions and sizes of the smallest basic stereoscopic shapes (cube or sphere) including all of the meshes belonging to each small space are determined. In the collision detection step, it is checked whether a haptic interface point (HIP) is included in a three-dimensional figure representing a group. When a collision with a specific three-dimensional figure is confirmed, searching is performed only for the meshes in the group to find a mesh on which a possible real collision with HIP occurred. The effectiveness of the proposed algorithm is verified by measuring and comparing the computation time of the proposed method with and without the proposed method.

Dual Codec Based Joint Bit Rate Control Scheme for Terrestrial Stereoscopic 3DTV Broadcast (지상파 스테레오스코픽 3DTV 방송을 위한 이종 부호화기 기반 합동 비트율 제어 연구)

  • Chang, Yong-Jun;Kim, Mun-Churl
    • Journal of Broadcast Engineering
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    • v.16 no.2
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    • pp.216-225
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    • 2011
  • Following the proliferation of three-dimensional video contents and displays, many terrestrial broadcasting companies have been preparing for stereoscopic 3DTV service. In terrestrial stereoscopic broadcast, it is a difficult task to code and transmit two video sequences while sustaining as high quality as 2DTV broadcast due to the limited bandwidth defined by the existing digital TV standards such as ATSC. Thus, a terrestrial 3DTV broadcasting with a heterogeneous video codec system, where the left image and right images are based on MPEG-2 and H.264/AVC, respectively, is considered in order to achieve both high quality broadcasting service and compatibility for the existing 2DTV viewers. Without significant change in the current terrestrial broadcasting systems, we propose a joint rate control scheme for stereoscopic 3DTV service based on the heterogeneous dual codec systems. The proposed joint rate control scheme applies to the MPEG-2 encoder a quadratic rate-quantization model which is adopted in the H.264/AVC. Then the controller is designed for the sum of the left and right bitstreams to meet the bandwidth requirement of broadcasting standards while the sum of image distortions is minimized by adjusting quantization parameter obtained from the proposed optimization scheme. Besides, we consider a condition on maintaining quality difference between the left and right images around a desired level in the optimization in order to mitigate negative effects on human visual system. Experimental results demonstrate that the proposed bit rate control scheme outperforms the rate control method where each video coding standard uses its own bit rate control algorithm independently in terms of the increase in PSNR by 2.02%, the decrease in the average absolute quality difference by 77.6% and the reduction in the variance of the quality difference by 74.38%.

QUANTITATIVE STUDY ON THE FEARFULNESS OF HUMAN DRIVER USING VECTOR QUANTIZATION

  • Kim, J.H.;Kim, Y.W.;Sim, K.Y.
    • International Journal of Automotive Technology
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    • v.8 no.4
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    • pp.505-512
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    • 2007
  • This paper presents the quantitative evaluation of the fearfulness of the human driver in the case of the short range (time) on the highway. The driving situation is realized by using the driving simulator based on CAVE, which provides three-dimensional stereoscopic immersive visual information. The examinees' responses and personal information are categorized reasonably by applying the competitive learning algorithm. The characteristics of each group are analyzed. The following two situations are also compared: (1) the active approaching situation where the examinee drives the vehicle near the preceding vehicle, and (2) the passive approaching situation where the preceding vehicle nears the examinee's vehicle by gradually decelerating. The range time that the examinee feels fear in the active approaching case tends to be shorter than that in the passive approaching case.

An Efficient Error Concealment Algorithm for Stereoscopic Videos (스테레오 비디오의 효율적인 오류 은닉 알고리즘)

  • Chung, Tae-Young;Kim, Chang-Su
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2010.07a
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    • pp.396-397
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    • 2010
  • 본 논문에서는 스테레오 비디오의 오류 복원 알고리즘을 제안한다. 제안하는 알고리즘은 시간적 시점간 상관관계를 동시에 고려하여 오류 블록을 복원한다. 시간적 상관관계가 있는 블록들의 디스패리티 벡터 유사성을 통해 움직임 벡터와 디스패리티 벡터를 예측하고, 시점간 상관관계가 있는 블록들의 움직임 벡터 유사성을 통해 디스패리티 벡터와 움직임 벡터를 예측한다. 예측된 벡터들로부터, 오류 블록의 인접 화소 값들과 가장 유사한 값을 갖는 시간 시점 후보 블록들을 찾고, 시간 시점후보 블록들을 조합하여 오류 블록을 복원한다. 제안하는 알고리즘이 스테레오 비디오를 위한 효과적인 오류 은닉 방법으로서 높은 복원 효율을 나타냄을 컴퓨터 모의실험을 통해 확인한다.

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Stereoscopic Image Retargeting Algorithm Preserving Depth Perception (입체감을 보존하는 스테레오 영상의 크기 조정 기법)

  • Lee, Seho;Chung, Tae-Young;Kim, Chang-Su
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2011.11a
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    • pp.129-130
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    • 2011
  • 본 논문에서는 입체감을 보존하여 스테레오 영상의 크기를 조정하는 기법을 제안한다. 스테레오 영상의 디스패리티 데이터를 이용하여 좌우 영상의 중요 영역을 추출하고, 영상의 빈 공간을 인페인팅(inpainting) 기법을 통해 복원한다. 복원된 배경 영역의 크기를 선형적으로 조정하고, 중요 영역은 최대한 보존하도록 크기를 조정하여 배경 영역에 붙여 넣는다. 실험 결과 제안하는 알고리즘이 기존 이미지 크기 조정 기법보다 스테레오 영상의 중요 정보와 입체감을 왜곡하지 않고 보존함을 확인할 수 있었다.

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