• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권11호
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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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.1140-1154
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• 2015

Multiple Description (MD) coding is a promising alternative for the robust transmission of information over error-prone channels. Lattice vector quantization (LVQ) is a significant version of MD techniques to design an MD image coder. However, different from the traditional 2D texture image, the 3D depth image has its own special characteristics, which should be taken into account for efficient compression. In this paper, an optimized MDLVQ scheme is proposed in view of the characteristics of 3D depth image. First, due to the sparsity of depth image, the image blocks can be classified into edge blocks and smooth blocks, which are encoded by different modes. Furthermore, according to the boundary contents in edge blocks, the step size of LVQ can be regulated adaptively for each block. Experimental results validate the effectiveness of the proposed scheme, which show better rate distortion performance compared with the conventional MDLVQ.

• 대한원격탐사학회지
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• 제22권5호
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• pp.351-356
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• 2006

Based on current practical needs for geo-spatial information on mobile platform, the main theme of this study is a design and implementation of dynamic 3D terrain rendering system using spaceborne imagery, as a kind of texture image for photo-realistic 3D scene generation on mobile environment. Image processing and 3D graphic techniques and algorithms, such as TIN-based vertex generation with regular spacing elevation data for generating 3D terrain surface, image tiling and image-vertex texturing in order to resolve limited resource of mobile devices, were applied and implemented by using graphic pipeline of OpenGL|ES (Embedded System) API. Through this implementation and its tested results with actual data sets of DEM and satellite imagery, we demonstrated the realizable possibility and adaptation of complex typed and large sized 3D geo-spatial information in mobile devices. This prototype system can be used to mobile 3D applications with DEM and satellite imagery in near future.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.895-898
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• 2002

In this paper, we propose a 3D image player for LCD monitors as well as CRT monitors. As we consider an afterglow and digital processing of LCD monitors, a stereoscopic images can be shown on CRT monitors as well as LCD monitors using the proposed a3D image player. We have implemented a 3D image player using FPGA (MAX 9320), We show prove that a stereoscopic images are shown on the LCD monitors.

• 한국콘텐츠학회논문지
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• 제11권4호
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• pp.11-17
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• 2011

본 논문 단일영상 내에 존재하는 피사체의 정보를 객관적인 수치로 구현하는 데 목적이 있다. 이러한 연구를 위해서 2차원의 단일영상이 가진 소실점을 기초로 하였으며, 3D 프로그램을 이용하여 단일영상을 3차원으로 재구성하였다. 또한, 3차원 재구성에 필요한 촬영카메라의 축 설정을 위해서 이미지가 가진 렌즈 화각 및 바닥 패턴을 활용하였다. 이렇게 완성된 3차원 영상은 하나의 기준이 되는 특정 피사체의 크기 값을 안다면 바닥패턴에 있는 모든 피사체의 크기 및 거리 측정이 가능하며 이를 통해 CCTV 또는 기타 범죄 사건의 영상에서 범인 및 단서가 되는 피사체의 기초정보를 획득할 수 있다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.318-324
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• 2000

Ultrasonic and magnetic resonance imaging systems are used to visualize the interior states of biological objects. These nondestructive methods have many advantages but too much expensive. And they do not give exact color information and may miss some details. If it is allowed to destruct some biological objects to get the interior and exterior information, constructing 3D image from the series of the sliced sectional images gives more useful information with relatively low cost. In this paper, PC based automatic 3D model generator was developed. The system was composed of three modules. One is the object handling and image acquisition module, which feeds and slices objects sequentially and maintains the paraffin cool to be in solid state and captures the sectional image consecutively. The second is the system control and interface module, which controls actuators for feeding, slicing, and image capturing. And the last is the image processing and visualization module, which processes a series of acquired sectional images and generates 3D graphic model. The handling module was composed of the gripper, which grasps and feeds the object and the cutting device, which cuts the object by moving cutting edge forward and backward. Sliced sectional images were acquired and saved in the form of bitmap file. The 3D model was generated to obtain the volumetric information using these 2D sectional image files after being segmented from the background paraffin. Once 3-D model was constructed on the computer, user could manipulate it with various transformation methods such as translation, rotation, scaling including arbitrary sectional view.

• Archives of Plastic Surgery
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• 제34권5호
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• pp.605-610
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• 2007

Purpose: Facial trauma is increasing along with increasing popularity in sports, and increasing exposure to crimes or traffic accidents. Compared to the 3D CT of 1990s, the latest CT has made significant improvement thus resulting in higher accuracy of diagnosis. The objective of this study is to compare 64 channel 3 dimensional volume CT(3D VCT) with conventional 3D CT in the diagnosis and treatment of facial bone fractures. Methods: 45 patients with facial trauma were examined by 3D VCT from Jan. 2006 to Feb. 2007. 64 channel 3D VCT which consists of 64 detectors produce axial images of 0.625 mm slice and it scans 175 mm per second. These images are transformed into 3 dimensional image using software Rapidia 2.8. The axial image is reconstructed into 3 dimensional image by volume rendering method. The image is also reconstructed into coronal or sagittal image by multiplanar reformatting method. Results: Contrasting to the previous 3D CT which formulates 3D images by taking axial images of 1-2 mm, 64 channel 3D VCT takes 0.625 mm thin axial images to obtain full images without definite step ladder appearance. 64 channel 3D VCT is effective in diagnosis of thin linear bone fracture, depth and degree of fracture deviation. Conclusion: In its expense and speed, 3D VCT is superior to conventional 3D CT. Owing to its ability to reconstruct full images regardless of the direction using 2 times higher resolution power and 4 times higher speed of the previous 3D CT, 3D VCT allows for accurate evaluation of the exact site and deviation of fine fractures.

• 한국방사선학회논문지
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• 제10권8호
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• pp.571-576
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• 2016

3D 프린팅은 최근 다양한 분야에서 활용 되고 있다. 다양한 활용 분야 중 사람의 얼굴을 3D 프린팅을 위해서는 먼저 3D 얼굴 데이터를 생성해야 한다. 3D 얼굴 데이터 획득을 위해 레이저 스캐너 등이 활용되고 있으나 스캔 중에 사람이 움직이면 안 되는 제약이 있다. 본 논문에서는 단일 영상 기반의 3D 얼굴 모델링 방법과 생성된 3D 얼굴을 가상 성형 등에 쓰일 수 있도록 얼굴 변형 시스템을 제안한다. 3D 얼굴 데이터 생성을 위해 3D 얼굴 데이터베이스로부터 특징점들을 정의하였다. 단일 얼굴 영상으로부터 얼굴을 특징점을 추출 한 후 3D 얼굴 데이터베이스로부터 정의된 3D 얼굴 특징점과 대응하여 입력 얼굴 영상의 3D 얼굴을 생성한다. 3D 얼굴 생성 후에 가상 성형 등의 용도를 위해 얼굴 변형 부분을 적용하였다.

• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.256-261
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• 2017

In this paper, we propose a modified smart pixel mapping (SPM) to visualize occluded three-dimensional (3D) objects in real image fields. In integral imaging, orthoscopic real 3D images cannot be displayed because of lenslets and the converging light field from elemental images. Thus, pseudoscopic-to-orthoscopic conversion which rotates each elemental image by 180 degree, has been proposed so that the orthoscopic virtual 3D image can be displayed. However, the orthoscopic real 3D image cannot be displayed. Hence, a conventional SPM that recaptures elemental images for the orthoscopic real 3D image using virtual pinhole array has been reported. However, it has a critical limitation in that the number of pixels for each elemental image is equal to the number of elemental images. Therefore, in this paper, we propose a modified SPM that can solve this critical limitation in a conventional SPM and can also visualize the occluded objects efficiently.

• Journal of information and communication convergence engineering
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• 제13권4호
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• pp.275-279
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• 2015

There are several methods to record three dimensional (3D) information of objects such as lens array based integral imaging, synthetic aperture integral imaging (SAII), computer synthesized integral imaging (CSII), axially distributed image sensing (ADS), and axially distributed stereo image sensing (ADSS). ADSS method is capable of recording partially occluded 3D objects and reconstructing high-resolution slice plane images. In this paper, we present a computational method for depth extraction of partially occluded 3D objects using ADSS. In the proposed method, the high resolution elemental stereo image pairs are recorded by simply moving the stereo camera along the optical axis and the recorded elemental image pairs are used to reconstruct 3D slice images using the computational reconstruction algorithm. To extract depth information of partially occluded 3D object, we utilize the edge enhancement and simple block matching algorithm between two reconstructed slice image pair. To demonstrate the proposed method, we carry out the preliminary experiments and the results are presented.