• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.19-24
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• 2019

Digital technologies in the digital image field are developing and changing rapidly while creating various forms of media environments. In particular, broadcasting image-processing technologies provide more realistic images through the development of multimedia technology. Consequently, the needs of flat image quality have been nearly met, leading to technological saturation. Currently, flat images possess the advantages of popularity and freedom from visual fatigue over three-dimensional stereoscopic images. A complementary technology for flat images is the stereoscopic perception improvement technology. To examine correlations between stereoscopic perception and colour attributes for graphic images on flat displays, we have conducted experiments related to stereoscopic perception and analysed the results. In these experiments, the colour attributes of hue, value, and chroma were applied at different levels. Next, the factors that provide the highest stereoscopic perception and their interactions were analysed through analysis of variance. Finally, this study defines the significance of colour factors related to stereoscopic perception by analysing the experimental results, and proposes a colour adjustment method for improved stereoscopic perception in graphics image processing.

• The KIPS Transactions:PartD
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• v.17D no.1
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• pp.59-66
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• 2010

Traditional OCR engines are designed to the scanned documents in calibrated environment. Three dimensional perspective distortion and smooth distortion in images are critical problems caused by un-calibrated devices, e.g. image from smart phones. To meet the growing demand of character recognition of texts embedded in the photos acquired from the non-calibrated hand-held devices, we address the problem in three categorical aspects: rotational invariant method of text region extraction, scale invariant method of text line segmentation, and three dimensional perspective mapping. With the integration of the methods, we developed an OCR for camera-captured images.

• Journal of Broadcast Engineering
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• v.21 no.1
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• pp.66-75
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• 2016

In this paper, we present a new method to reduce crosstalk of a glasses-free three-dimensional (3D) display using a multi-view image processing technique. Since crosstalk makes the current view image mixed with its neighboring ones, the output 3D image becomes severely blurred. We apply adaptive depth retargeting and view gradient-based crosstalk inverse filtering onto a multi-view image to minimize crosstalk of the glasses-free 3D display. In addition, overflow and underflow pixels are compensated by epipolar image pixel interpolation so that visual artifacts are minimized. Experimental results show that the proposed method reduces crosstalk more efficiently than the previous work while improving 3D image quality.

• Imaging Science in Dentistry
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• v.53 no.4
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• pp.325-333
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• 2023

Purpose: The objective of this study was to evaluate and compare the accuracy and image quality of root surface area (RSA) measurements obtained with various cone-beam computed tomography (CBCT) protocols, relative to the gold standard of micro-computed tomography (CT), in an in vitro setting. Materials and Methods: Four dry human skulls were scanned using 8 different protocols, with voxel sizes of 0.15 mm, 0.3 mm, and 0.4 mm. Three-dimensional models of the selected teeth were constructed using CBCT and microCT protocols, and the RSA was automatically measured by the image-processing software. The absolute difference in the percentage of the RSA(%ΔRSA) was calculated and compared across the 8 CBCT protocols using repeatedmeasures analysis of variance. Finally, image quality scores of the RSA measurements were computed and reported in terms of percent distribution. Results: No significant differences were observed in the %ΔRSA across the 8 protocols (P>0.05). The deviation in %ΔRSA ranged from 1.51% to 4.30%, with an increase corresponding to voxel size. As the voxel size increased, the image quality deteriorated. This decline in quality was particularly noticeable at the apical level of the root, where the distribution of poorer scores was most concentrated. Conclusion: Relative to CBCT protocols with voxel sizes of 0.15mm and 0.3mm, the protocols with a voxel size of 0.4 mm demonstrated inferior image quality at the apical levels. In spite of this, no significant discrepancies were observed in RSA measurements across the different CBCT protocols.

• Journal of Digital Contents Society
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• v.12 no.2
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• pp.151-156
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• 2011

The analysis and image evaluation the Ray-sum technique and Shaded Surface Display (under SSD) technique which is the reconstruction image processing technique after the CT scan was evaluated and the usability of the three-dimensional information offering was confirmed in the patient with stomach cancer. After obtaining the raw data by using 64-MDCT in 20 patient with stomach cancers, the image reconstruction processing was done. It was evaluated to describe accurately the analyzed result Ray-sum and SSD reconstruction image everyone anatomical structure. In the precision estimation of the image, the lesion location could coincide in the Ray-sum and SSD reconstruction image majority with the gastro fiberscope and we can know than the gastro fiberscope over 6cm that there was the error. In addition, We could know that degree of accordance of the results of the image interpretation about the lesion and endoscope and pathological opinion were high.

• Journal of Computational Design and Engineering
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• v.1 no.4
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• pp.272-288
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• 2014

This paper presents a two-step, semi-automated method for reconstructing a three-dimensional (3D) shape of the prostate from a 3D transrectal ultrasound (TRUS) image. While the method has been developed for prostate ultrasound imaging, it can potentially be applicable to any other organ of the body and other imaging modalities. The proposed method takes as input a 3D TRUS image and generates a watertight 3D surface model of the prostate. In the first step, the system lets the user visualize and navigate through the input volumetric image by displaying cross sectional views oriented in arbitrary directions. The user then draws partial/full contours on selected cross sectional views. In the second step, the method automatically generates a watertight 3D surface of the prostate by fitting a deformable spherical template to the set of user-specified contours. Since the method allows the user to select the best cross-sectional directions and draw only clearly recognizable partial or full contours, the user can avoid time-consuming and inaccurate guesswork on where prostate contours are located. By avoiding the usage of noisy, incomprehensible portions of the TRUS image, the proposed method yields more accurate prostate shapes than conventional methods that demand complete cross-sectional contours selected manually, or automatically using an image processing tool. Our experiments confirmed that a 3D watertight surface of the prostate can be generated within five minutes even from a volumetric image with a high level of speckles and shadow noises.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.347-351
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• 2010

In this paper, our effort to apply 3-D Virtual Reality system for stereoscopic visualization of flow data is briefly described. This study is an extension of our previous and on-going research efforts to develop DATA(Data Analysis and Visualization Application) program, which is a data visualization program developed by using Qt as GUI development environment and OpenGL as graphic library. The program is developed upon the framework of object-oriented programming and it was originally developed by using Qt 3.3.3 environment. In this research the program is converted into a Qt 4.3.3-compatible version, and this new version is developed on Visual Studio 2005. And to achieve a stereoscopic viewing capability, two graphic windows are used to render its own viewing image for the lift and right eye respectively. These two windows are merged into one image using 3D monitor and the viewers can see the data visualization results with stereoscopic depth effects by using polarizing glasses. In this paper three dimensional data visualization with stereoscopic technique combined with 3D Monitor is demonstrated, and the current achievement would be a good start-up for further development of low-cost high-quality stereoscopic data visualization system.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.2
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• pp.59-64
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• 2014

This paper presents a method for estimating the bounding volume for image-based 3D object reconstruction. The bounding volume of an object is a three-dimensional space where the object is expected to exist, and the size of the bounding volume strongly affects the resolution of the reconstructed geometry. Therefore, the size of a bounding volume should be as small as possible while it encloses an actual object. To this end, the proposed method uses a set of silhouettes of an object and generates a point cloud using a point filter. A bounding volume is then determined as the minimum sphere that encloses the point cloud. The experimental results show that the proposed method generates a bounding volume that encloses an actual object as small as possible.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.2
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• pp.277-284
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• 2004

This paper describes the influence of through-flow on the mixed convection in a parallel plates with the upper part is cooled and the lower part heated. When forced convection is imposed on natural convection, it is found that the flow pattern of mixed convection in the parallel plates can be classified into three patterns which were affected by Reynolds number. In such a mixed convection, the flow pattern plays an important role in the heat transfer process. In this study, thermo-sensitive liquid crystal suspension method is employed, then the visualization image acquired through the above method is processed by the color image processing technique and the two-dimensional velocity vector and temperature configuration are measured simultaneously.

• Applied Microscopy
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• v.44 no.3
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• pp.83-87
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• 2014

Electron tomography (ET) is a useful tool to investigate three-dimensional details based on virtual slices of relative thick specimen, and it requires complicated procedures consisted of image acquisition steps and image processing steps with computer program. Although the complicated step, this technique allows us to overcome some limitations of conventional transmission electron microscopy: (1) overlapping of information in the ultrathin section covering from 30 nm to 90 nm when we observe very small structures, (2) fragmentation of the information when we study larger structures over 100 nm. There are remarkable biological findings with ET, especially in the field of neuroscience, although it is not popular yet. Understanding of behavior of synaptic vesicle, active zone, pooling and fusion in the presynaptic terminal have been enhanced thanks to ET. Some sophisticated models of postsynaptic density with ET and immune labeling are introduced recently. In this review, we introduce principles, practical steps of ET and some recent researches in synapse biology.