• Journal of Broadcast Engineering
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• v.17 no.2
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• pp.316-324
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• 2012

In this paper, a novel descreening method using HOG(histogram of gradient)-based adaptive smoothing filter is proposed. Conventional edge-oriented smoothing methods does not provide enough smoothing to the halftone image due to the edge-like characteristic of the halftone noise. Moreover, clustered-dot halftoning method, which is commonly used in printing tends to create Moire pattern because of the intereference in color channels. Therefore, the proposed method uses HOG to distinguish edges and the amount of smoothing to be performed on the halftone image is then calculated according to the magnitude of the HOG in the edge and edge normal orientation. The proposed method was tested on various scanned halftone materials, and the results show that it effectively removes halftone noises as well as Moire pattern while preserving image details.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.298-303
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• 2008

Watching a program on IPTV among the numerous choices from the internet requires a burden of searching and browsing for a favorite one. This paper introduces a new concept called Mosaic Map and presents how it provides preview information of image map links to other programs. In Mosaic Map the pixels in the still image are used both as shading the background and as thumbnails which can link up with other programs. This kind of contextualized preview of choices can help IPTV users to associate the image with related programs without making visual saccades between watching IPTV and browsing many choices. The experiments showed that the Mosaic Map reduces the time to complete search and browsing, comparing to the legacy menu and web search.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4C
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• pp.437-445
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• 2009

Node of USN(Ubiquitous Sensor Network) environments uses radio based communication mechanism for a delivering message. Thus the multiple hop flooding is necessary for considering limited power and communicating unknown node long-range. However if there are many unknown nodes located in users' vision, the flooding of the radio base is insufficient alternative. Thus as a flash may be used to find a key in a darkness, a more direct and short range communication system is required. This study shall resolve such question through 2 different steps. First a Two kind of code method that convert Text message to color code shall be suggested. Second a hardware module, which may deliver various LED(light-emitting diode) color signal, shall be developed. The experiment may take place by fixing the entry angle of light and distance by setting a specific element as a standard mean.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.175-186
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• 2018

Due to global warming, various natural disasters such as floods and localized heavy rains are increasing. If a natural disaster can be detected and analyzed in advance and effectively, it can prevent enormous damage due to natural disasters. Recent development in visual sensor technologies has encouraged various studies on monitoring environments including rivers. In this paper, we propose a method to detect river regions from river images which can be exploited for river surveillance systems using video sensor networks. In the proposed method, we first analyze the color properties of the river region and the background region of a image and then propose a way to select the proper color channel and binarize the image to detect the river region. It is shown by experimental results that the proposed method is simple but detects river regions accurately.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5A
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• pp.325-338
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• 2012

In this paper, a radio resource allocation scheme for a multi-hop relay transmission in cognitive radio (CR) system is proposed to support the employment of relay nodes in IEEE 802.22 standard for wireless regional area network (WRAN). An optimization problem is formulated to maximize the number of serving secondary users (SUs) under system constraints such as time-divided frame structure for multiplexing and a single resource-unit to every relay-hop. However, due to mathematical complexity, the optimization problem is solved with a sub-optimal manner instead, which takes three steps in the order of user selection, relay/path selection, and frequency selection. In the numerical analysis, this proposed solution is evaluated in terms of service rate denoting as the ratio of the number of serving SUs to the number of service-requesting SUs. Simulation results show the condition of adopting multi-hop relay and the optimum number of relaying hops by comparing with the performance of 1-hop system.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.70-77
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• 2022

This paper proposes database generation and management system for small-pixelized airborne target recognition. The proposed system has five main features: 1) image extraction from in-flight test video frames, 2) automatic image archiving, 3) image data labeling and Meta data annotation, 4) virtual image data generation based on color channel convert conversion and seamless cloning and 5) HOG/LBP-based tiny-pixelized target augmented image data. The proposed framework is Python-based PyQt5 and has an interface that includes OpenCV. Using video files collected from flight tests, an image dataset for airborne target recognition on generates by using the proposed system and system input.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.5
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• pp.103-111
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• 2007

In this paper, we propose a VLSI architecture of hardware optimized high quality image signal processor for a Single-chip CMOS Image Sensor(CIS). The Single-chip CIS is usually used for mobile applications, so it has to be implemented as small as possible while maintaining the image quality. Several image processing algorithms are used in ISP to improve captured image quality. Among the several image processing blocks, demosaicing and image filter are the core blocks in ISP. These blocks need line memories, but the number of line memories is limited in a low cost Single-chip CIS. In our design, high quality edge-adaptive and cross channel correlation considered demosaicing algorithm is adopted. To minimize the number of required line memories for image filter, we share the line memories using the characteristics of demosaicing algorithm which consider the cross correlation. Based on the proposed method, we can achieve both high quality and low hardware complexity with a small number of line memories. The proposed method was implemented and verified successfully using verilog HDL and FPGA. It was synthesized to gate-level circuits using 0.25um CMOS standard cell library. The total logic gate count is 37K, and seven and half line memories are used.

• Cartoon and Animation Studies
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• s.14
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• pp.37-51
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• 2008

The computer has become an indispensable tool for animation works. However if you don't understand the characteristics of the computer and its software, you might not have the result satisfying your efforts. The incorrect understanding of image format sometimes causes it. Habitually image formats are selected usually for most of works but there is a distinct difference among those image formats while the efficient usages of them are different from each other. For your more efficient work therefore, you need to identify the characteristics of various kinds of image format used mostly for animation works. First I took a look at the theories of the lossy compression and lossless compression, which are two types of data compression widely used in the whole parts of computer world and the difference between bitmap method and vector method, which are respectably different in terms of the way of expressing images and finally the 24 bit true color and 8 bits alpha channel. Based on those characteristics, I have analyzed the functional difference among image formats used between various types of animation works such as 2D, 3D, composing and editing and also the benefits and weakness of them. Additionally I've proved it is wrong that the JPEG files consume a small space in computer work. In conclusion, I suggest the TIF format as the most efficient format for whatever it is editing, composing, 3D and 2D in considering capacity, function and image quality and also I'd like to recommend PSD format which has compatibility and excellent function, since the Adobe educational programs are used a lot for the school education. I hope this treatise to contribute to your right choice of image format in school education and practical works.