• Journal of Korea Multimedia Society
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• v.12 no.2
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• pp.219-230
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• 2009

With the development of broadcasting technology from analogue to interactive digital, the number of TV channels and TV contents provided to audiences is increasing in a rapid speed. In this multi-channel world, it is difficult to adapt to the increase of the TV channel numbers and their contents merely using remote controller to search channels. For these reasons, the EPG system, one of the essential services providing convenience to audiences, is proposed in this paper. Collaborative filtering method with multi-step filtering is used in EPG to recommend contents according to the preference of audience groups with similar preference. To implement our designed TV contents recommendation EPG, we prefer DiTV and use JavaXlet programming based on MHP. The European DVB-MHP specification will be also our domestic standard in DiTV. Finally, the result is verified by OpenMHP emulator.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.4 s.38
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• pp.19-26
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• 2006

This study assessed the accuracies of the ground information extracting methods from the LiDAR data. Especially, it compared two kinds of method, one of them is using directly the raw LiDAR data which is point type vector data and the other is using changed data to DSM type as the normal grid type. The methods using Local Maxima and Entropy methods are applied as a former case, and for the other case, this study applies the method using edge detection with filtering and the generated reference surface by the mean filtering. Then, the accuracy assessment are performed with these results, DEM constructed manually and the error permitted limit in scale of digital map. As a results, each DEM mean errors of methods using edge detection with filtering, reference surface, Local Maxima and Entropy are 0.27m, 2.43m, 0.13m and 0.10m respectively. Hence, the method using entropy presented the highest accuracy. And an accuracy from a method directly using the raw LiDAR data has higher accuracy than the method using changed data to DSM type relatively.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.4 s.34
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• pp.27-32
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• 2005

DEM is needed for urban modeling, forecasting of floods and the analysis of slope and aspect. It has been generated using digital maps, aerial photos or satellite imageries. Recently, however, many studies on DEM generation from LiDAR data has been conducted because of its efficiency and accuracy. Filtering is said to be the process of making DEM by eliminating non-ground points from LiDAR data. In most researches, some input parameters such as the size of filter are required. The purpose of this investigation is to automatically obtain DEM by eliminating objects of various sizes without the knowledge of the objects' sizes. The experimental results show that most of objects on steep terrain are eliminated by the proposed method.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.251-258
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• 2014

The purpose of the neural image analysis is to trace the velocities and the directions of moving mitochondria migrating through axons. This paper proposes an automated technique for detecting axon structure. Previously, the detection process has been carried out using a partially automated technique combined with some human intervention. In our algorithm, a consolidated image is built by taking the maximum intensity value on the all image frames at each pixel Axon detection is performed through vessel enhancement filtering followed by a peak detection procedure. In order to remove errors contained in ridge points, a filtering process is devised using a local reliability measure. Experiments have been performed using real neural image sequences and ground truth data extracted manually. It has been turned out that the proposed algorithm results in high detection rate and precision.

• Journal of Broadcast Engineering
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• v.13 no.5
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• pp.662-676
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• 2008

This paper presents a video copy detection algorithm that blocks online transfer of illegally copied DTV broadcast programs. Particularly, the proposed algorithm establishes a set of keyframes by detecting abrupt changes of luminance, and then exploits the spatio-temporal features of keyframes. Comparing with the preregistered features stored in the database of DTV broadcast programs, the proposed scheme performs a function of video filtering in order to distinguish whether an uploaded video is illegally copied or not. Note that we analyze only a set of keyframes instead of an entire video frame. Thus, it is highly efficient to identify illegal copied video when we deal with a vast size of broadcast programs. Also, we confirm that the proposed technique is robust to a variety of video edit-effects that are often applied by online video redistribution, such as apsect-ratio change, logo insertion, caption insertion, visual quality degradation, and resolution change (downscaling). In addition, we perform a benchmark test in which the proposed scheme outperforms previous techniques.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.4
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• pp.249-254
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• 2007

This paper describes a technique for detecting the boundary of the optic disk in digital image of the retina using inward and outward curve evolution. Optic disk boundary offers medical information about glaucoma progresses. For accurate boundary detection, image inpainting based on PDE removes blood vessels crossing the optic disk. For removing noises and preserving boundary of optic disk in image inpainting process, the anisotropic diffusion filtering is developed. After pre-processing, the optic disk boundary is determined using inward and outward curve evolution. Experimental results show that blurring effect of original region and optic disk boundary is reduced considerably. By the proposed method, we can detect correct disk boundary compare to conventional method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.551-558
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• 2014

Baseline drift reduction and removal of power line noises in electrocardiogram are often necessary to avoid the distortions in extracting the fiducial features. With this aim, the multirate digital filtering algorithm is suggested to design and implement Finite Impulse Response or Infinite Impulse Response Filter by changing the sampling rate with omitting or interpolating intermediate ECG data. After the experimental simulations performed, we can conclude the fact that we can suppress the baseline wander and power line disturbances in ECG signal with reducing the computational complexities in which we do not keep the original and high sampling frequency.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.23-26
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• 2003

디지털로 신호를 표현하는 방법은 기존 아날로그 표현하는 방법에 비해 많은 장점을 가지고 있다. 하지만 디지털로 된 데이터는 언제 어디서든 대단위 복제가 가능하다. 즉, 저작권 침해, 불법 복제 및 배포, 손쉽게 위조할 수 있다는 점이 그것이다. 디지털 영상 정보의 보호를 위해 디지털 영상의 불법적인 내용 조작을 막고, 영상의 소유권을 보장할 수 있는 방법으로 디지털 워터마크(Digital Watermark)가 있다. 디지털 워터마크는 공개키 알고리즘이나 방화벽 등으로 해독된 영상에 대하여 부가적인 보호를 제공한다. 본 논문에서는 디지털 영상 데이터의 정보 보호를 위해 주파수 영역에서의 웨이브릿 변환(Wavelet Transform)을 이용한 이미지 적용 디지털 워터마킹(Image-Adaptive Digital Watermarking) 방법을 제안한다. 이미지 적용 웨이브릿(Image-Adaptive Wavelet)은 영상을 주파수적으로 분해하면서 각 대역들의 공간 영역에서의 정보를 함께 지니고 JND(Just noticeable difference)을 포함한다. 이미지 적응 웨이브릿의 이러한 특성을 이용하여 다해상도 분해하고, 손실 압축(Loss Compression)이나 필터링(Filtering), 잡음(Noise)등에 크게 영향받는 저주파 성분과 인간의 시각적으로 큰 의미를 갖는 고주파 성분의 특성을 이용하여 워터마크를 삽입한다.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.2
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• pp.131-143
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• 2012

This paper introduces the double-density discrete wavelet transform using 3 direction separable processing method, which is a discrete wavelet transform that combines the double-density discrete wavelet transform and quincunx sampling method, each of which has its own characteristics and advantages. The double-density discrete wavelet transform is nearly shift-invariant. But there is room for improvement because not all of the wavelets are directional. That is, although the double-density DWT utilizes more wavelets, some lack a dominant spatial orientation, which prevents them from being able to isolate those directions. The dual-tree discrete wavelet transform has a more computationally efficient approach to shift invariance. Also, the dual-tree discrete wavelet transform gives much better directional selectivity when filtering multidimensional signals. But this transformation has more cost complexity Because it needs eight digital filters. Therefor, we need to hybrid transform which has the more directional selection and the lower cost complexity. A solution to this problem is a the double-density discrete wavelet transform using 3 direction separable processing method. The proposed wavelet transformation services good performance in image and video processing fields.

• ETRI Journal
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• v.33 no.2
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• pp.275-278
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• 2011

This letter presents a polymer $1{\times}2$ thermo-optic totalinternal-reflection digital optical switch (TIR-DOS) with an index contrast of 1.5%-${\delta}$ operating at low power consumption. The structure of our $1{\times}2$ TIR-DOS was created by adding a reflection port to that of a conventional multimode filtering variable optical attenuator. To improve the total-internalr-eflection efficiency, a heater offset was applied to the crossing region of multimode waveguides of the TIR-DOS. The fabricated $1{\times}2$ TIR-DOS shows a low electrical power consumption of 18 mW for an on-off ratio of 35 dB.