• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.06a
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• pp.63-66
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• 2018

Recently, a convolutional neural network (CNN) models at single image super-resolution have been very successful. Residual learning improves training stability and network performance in CNN. In this paper, we compare four convolutional neural network models for super-resolution (SR) to learn nonlinear mapping from low-resolution (LR) input image to high-resolution (HR) target image. Four models include general CNN model, global residual learning CNN model, local residual learning CNN model, and the CNN model with global and local residual learning. Experiment results show that the results are greatly affected by how skip connections are connected at the basic CNN network, and network trained with only global residual learning generates highest performance among four models at objective and subjective evaluations.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.272-275
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• 2020

Light Field (LF) cameras capture both spatial and directional information of light rays. Current LF cameras have a problem of a low spatial resolution. There have been lots of existing works carried out to improve the resolution of LF images. In this paper, those existing works will be divided into two categories: hardware-based approaches and software-based approaches, and we will look into and compare several experiment results in order for LF spatial resolution enhancement. Finally, the direction for the future spatial resolution enhancement will be suggested.

• ETRI Journal
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• v.29 no.3
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• pp.311-321
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• 2007

In this paper, we propose a user-centric conflict management method for media services which exploits personal companions for the harmonious detection and resolution of service conflicts. To detect conflicts based on the varying characteristics of individual users, the proposed method exploits the unified context describing all users attempting to access media services. It recommends and mediates users' preferred media contents through a shared screen and personal companions to resolve the detected conflicts. During the recommendation, a list of preferred media contents is displayed on the shared screen, and a personally preferred content list is shown on the user's personal companion comprising the selection of media contents. Mediation assists the selection of a consensual service by gathering the users' selections and highlighting the common media contents. In experiments carried out in a ubiHome, we observed that recommendations and mediation are useful in harmoniously resolving conflicts by encouraging user participation in conflict situations.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.44.1-44.1
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• 2012

Clusters of galaxies are the largest virialized structures in the universe, which serve as laboratories for the study of astrophysical processes on very large scales. Observations and theoretical arguments suggest that intracluster media is turbulent. The media are very hot and dynamic, highly rarefied, and probably magnetized at some level. The physics involved is complex and high-resolution simulations help us understand the physics and consequent phenomena. We are engaged in a simulation study designed to understand in this context how subsonic turbulence with very weak initial magnetic fields develops and evolves with imposed forcing. We find that the resulting turbulence is sensitive to the nature of forcing as well as the dissipation properties of the media.

• Journal of Broadcast Engineering
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• v.23 no.1
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• pp.74-85
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• 2018

The research investigated the interaction effect of video resolution and device luminance on the perceived characteristics, presence, and fatigue viewing virtual reality. Experiments were composed of mixed design, and the resolution and luminance were classified into three types, HD, 2K, and 4K, and 20, 60, and 100, respectively. Participants watched video of 6-minutes randomly, and responded to the questionnaire after watching each video. The results showed that no interaction effect existed. Meanwhile, there are statistically significant differences on the luminance of depth perception, the resolution of visual intervention, and the resolution of adjustment fatigue. Also, higher resolution and luminance showed higher cognitive function, presence and fatigue.

• Journal of the Korea Computer Graphics Society
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• v.13 no.4
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• pp.7-12
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• 2007

With the advent of digital cinema, more and more movies are digitally produced, distributed via digital medium such as hard drives and network, and finally projected using a digital projector. However, digital cameras capable of shotting at 2K or higher resolution for digital cinema are still very expensive and bulky, which impedes rapid transition to digital production. As a low-cost solution for acquiring high resolution digital videos, we propose a hybrid camera consisting of a low-resolution CCD for capturing videos and a high-resolution CCD for capturing still images at regular intervals. From the output of the hybrid camera, we can synthesize high-resolution videos by software as follows: for each frame, 1. find pixel correspondences from the current frame to the previous and subsequent keyframes associated with high resolution still images, 2. synthesize a high-resolution image for the current frame by copying the image blocks associated with the corresponding pixels from the high-resolution keyframe images, and 3. complete the synthesis by filling holes in the synthesized image. This framework can be extended to making NPR video effects and capturing HDR videos.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1738-1743
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• 2017

This paper presents an efficient image stitching method using preprocessing in order to generate a super resolution image. Two-dimensional (2D) scanners are consistently used in various areas but they have limitations such as paper sizes and materials. To overcome these problem with low-cost, an efficient imaging stitching method is proposed for producing a super resolution panorama image. To scan a very large sized paper using mobile phones, a simple portable cradle which fixes height is employed producing an input image set. To improve matching performance, a preprocessing method is introduced before searching correspondences. Then alpha blending is applied to an input image set to produce a super resolution panorama image. The proposed method is faster and easier than the existing method which is employed by Open CV. Experiment results show that the proposed method is three times faster and performs better than the existing method.

• Smart Media Journal
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• v.9 no.4
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• pp.134-143
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• 2020

Vehicle License Plate Recognition is one of the approaches for transportation and traffic safety networks, such as traffic control, speed limit enforcement and runaway vehicle tracking. Although it has been studied for decades, it is attracting more and more attention due to the recent development of deep learning and improved performance. Also, it is largely divided into license plate detection and recognition. In this study, experiments were conducted to improve license plate detection performance by utilizing various object detection methods and WPOD-Net(Warped Planar Object Detection Network) model. The accuracy was improved by selecting the method of detecting the vehicle(s) and then detecting the license plate(s) instead of the conventional method of detecting the license plate using the object detection model. In particular, the final performance was improved through the process of removing noise existing in the image by using the Fast-SRGAN model, one of the Super-Resolution methods. As a result, this experiment showed the performance has improved an average of 4.34% from 92.38% to 96.72% compared to previous studies.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.142-152
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• 2019

There is growing interest in ultra-high-resolution content that gives a more realistic sense of presence than existing broadcast content. However, in order to provide ultra-high-resolution contents in existing broadcast services, there are limitations in view angle and resolution of the image acquisition device. In order to solve this problem, many researches on stitching, which is an image synthesis method using a plurality of input devices, have been conducted. In this paper, we propose method of dynamic object based video stitching using minimal error seam in order to overcome the temporal invariance degradation of moving objects in the stitching process of horizontally oriented videos.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.661-663
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• 2003

In this paper, we present new methods for rapid high-resolution range sensing using green-blue stripe pattern. We use green and blue for designing high-frequency stripe projection pattern. For accurate and reliable range recovery, we identify the stripe patterns by our color-stripe segmentation and unwrapping method. The experimental result for a naked human face shows the effectiveness of our method.