• Journal of Multimedia Information System
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• v.4 no.2
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• pp.65-73
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• 2017

This paper proposes a method to improve the image quality by designing Unsharp Mask Filter (UMF) based on Retinex theory which controls the frequency pass characteristics adaptively. Conventional unsharp masking technique uses blurring image to emphasize sharpness of image. Unsharp Masking(UM) adjusts the original image and sigma to obtain a high frequency component to be emphasized by the difference between the blurred image and the high frequency component to the original image, thereby improving the contrast ratio of the image. In this paper, we design a Unsharp Mask Filter(UMF) that can process the contrast ratio improvement method of Unsharp Masking(UM) technique with one filtering. We adaptively process the contrast ratio improvement using Unsharp Mask Filter(UMF). We propose a method based on Retinex theory for adaptive processing. For adaptive filtering, we control the weights of Unsharp Mask Filter(UMF) based on the human visual system and output more effective results.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.6
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• pp.81-90
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• 1994

Finite element analysis is performed for transient thermal deformation of a shadow mask inside the Braun tube and the landing shift or mislanding of the electronic beam is calclated. The shadow mask has numerous slits through which the electronic beams are guided to land on the designed phosphor. Its thermal deformations therefore cause the mislanding of the electronic beam and result in decolorization of a screen. For realistic finite element analysis, firstly the effective thermal conductivity and the effective elastric modulus are calculated, and the shadow mask is modeled as shell without slits. Next the nonlinear finite element formulation is developed for transient heat transfer on the shadow mask, wherein thermal radiation is a major heat transfer mechanism. Analysis of the resulting thermoelastic deformations is followed, from which the mislanding of the electronic beam is obtained. The present finite element scheme may be efficiently used for thermal deformation design of a shadow mask.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.4
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• pp.243-248
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• 2022

The purpose of this paper is to etching SUS MASK by adding an additive (F300) to FeCl3. The equipment used in the experiment is a self-made automatic liquid management system. The automatic liquid management system is a device capable of controlling the Oxidation Reduction Potential (ORP) and specific gravity in real time and supplying FeCl3 and additives in a quantitative manner. SUS MASK was etched in units from 10 sheets up to 200 sheets for 1 minute. It was confirmed that when the initial SUS MASK was 10 sheets, the ORP value started with 628 mV and measured at 611 mV from the time of 40 sheets being injected, and maintained close to 610 mV up to 200 sheets. The specific gravity was maintained near 1.640. And the SUS MASK was measured close to 0.4 mm from 50 sheets to 200 sheets. The experimental conditions of ORP had a specific gravity of 610 mV, 1.463, an etching pressure of 3.0 kg/cm2, an additive (F300) ratio of 1.2%, and the hole size was measured by up to 200 sheets of 10 sheets at once etching. As a result, the diameter approached 0.4 mm from 20 sheets. Even if the number of SUS MASK was increased, the ORP and specific gravity were well controlled, and it was confirmed that the experimental target value was close to 0.4 mm.

• Journal of Internet Computing and Services
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• v.20 no.5
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• pp.105-111
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• 2019

Core technologies that lead the Fourth Industrial Revolution era, such as artificial intelligence, big data, and autonomous driving, are implemented and serviced through the rapid development of computing power and hyper-connected networks based on the Internet of Things. In this paper, we implement two different models for drivable area segmentation in various environment, and propose a better model by comparing the results. The models for drivable area segmentation are using DeepLab V3+ and Mask R-CNN, which have great performances in the field of image segmentation and are used in many studies in autonomous driving technology. For driving information in various environment, we use BDD dataset which provides driving videos and images in various weather conditions and day&night time. The result of two different models shows that Mask R-CNN has higher performance with 68.33% IoU than DeepLab V3+ with 48.97% IoU. In addition, the result of visual inspection of drivable area segmentation on driving image, the accuracy of Mask R-CNN is 83% and DeepLab V3+ is 69%. It indicates Mask R-CNN is more efficient than DeepLab V3+ in drivable area segmentation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.1
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• pp.9-18
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• 1987

An electro-optic system using linear photosensitive Charge Coupled Devices(CCDs) having dummy pixels has been proposed for realzation of linear prodictor in the differential pulse code modulation(DPCM). The system consists of three components as conventional system:input light source, spatial filter(mask) and CCD line scanning sensor. For the delay time due to the dummy pixels in CCD, modifying conventional mask, a new dispersive mask is proposed, of which every prediction coefficient is dispersed on the more than one element, the characteristics of the system using the proposed dispersive mask are analyzed theoretically and verified with experiment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.892-894
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• 2013

Edge has been utilized in various application fields with development of technique of digital image processing. In conventional edge detection methods, there are some methods using mask including Sobel, Prewitt, Roberts and Laplacian operator. Those methods are that implement is simple but generates errors of edge detection in images added AWGN(additive white Gaussian noise). Therefore, to compensate the defect of those methods, in this paper, an edge detection algorithm using modified mask is proposed, and it showed superior edge detection property in AWGN.

• Transactions of the Society of Information Storage Systems
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• v.1 no.2
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• pp.143-149
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• 2005

In this paper we propose a novel volume hologram encryption system with binary amplitude masks rather than phase masks, in which volume holograms can be securely recorded against the attacks by a third party. In our system, the encryption is done by multiplexing two volume holograms in such a way that an original binary data page is first stored as a volume hologram by interference with a binary amplitude mask and then the complementary data page is stored as another volume hologram by interference with the complementary binary amplitude mask over the first hologram. The operation principle of our system is explained with the well-known theory of recording and reading a volume hologram in a photorefractive material and the experimental results are presented. Experimental data show that our encryption system is protected from blind decryptions by randomly-generated incorrect amplitude masks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1603-1610
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• 1999

본 논문은 CMOS의 latch-up 특성을 개선하기 위한 효과적인 mask 설계 방법에 관한 것이다. Mask의 평면구조와 latch-up 파라메타와의 상관관계를 실물 제작에 의한 실험과 컴퓨터 시뮬레이션에 의해 도출하였으며, guard ring의 효과에 대해서도 비교 분석하였다. 실험 결과, 수평구조 바이폴라 트랜지스터의 전류증폭률($\beta$n)이 디자인룰에 반비례하였으며, 수직구조 바이폴라 트랜지스터의 전류증폭률($\beta$n)은 디지인룰과 무관하였다. 스위칭전압과 유지전류는 디자인룰에 비례하였다. Guard ring은 latch-up의 가능성을 줄이는 데 상당한 효과가 있었음이 확인되었으며, Guard ring이 없는 경우에 비하여 전류증폭률의 곱($\beta$n$\beta$n)이 약 31% 감소, 유지전류는 약 25%가 향상됨을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.1
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• pp.29-36
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• 2004

Generally, wavelet coefficients can be classified into two categories: large coefficients with much signal information and small coefficients with little signal component. This statistical characteristic of wavelet coefficient is approximated to Gaussian mixture model and efficiently applied to noise reduction. In this paper, we propose an image denoising method using mixture modeling of wavelet coefficients. Binary mask value is generated by proper threshold which classifies wavelet coefficients into two categories. Information of binary mask value is used to remove image noise. We also develope an enhancement method of mask value using morphological filter, and apply it to image denoising for improvement of the proposed method. Simulation results shows the proposed method have better PSNRs than those of the state of art denoising methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.328-330
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• 2015

Edge is a characteristic information that can easily obtain the size, direction and location of objects included in the image, and the edge detection is utilized as a preprocess processing in various image processing application sectors such as object detection and object recognition, etc. For the conventional edge detection methods, there are Sobel, Prewitt and Roberts. These existing edge detection methods are easy to implement but the edge detection characteristics are somewhat insufficient as fixed weighted mask is applied. Therefore, in order to compensate the problems of existing edge detection methods, in this paper, an edge detection algorithm was proposed after applying the weighted value according to the standard deviation and means within the local mask.