• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.11a
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• pp.169-171
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• 2011

최근 통신 환경의 진화와 고사양 모바일 단말기의 대중화로 인하여 모바일 통신 환경에서 동영상 서비스를 이용하는 사용자가 급증하고 있다. 사용자들은 제한적인 데이터 사용량을 이용하여 필요한 영상을 효율적으로 검색 및 탐색하기 위하여 미리보기 서비스 또는 Thumbnail을 이용한다. 이 중 Thumbnail은 동영상의 복호화 과정에서 제공되는 서비스이며, 이를 효과적으로 추출하는데 있어서 낮은 복잡도의 기술들이 사용되어야 한다. 본 논문에서는 영상의 히스토그램의 특징을 이용한 Thumbnail 추출 기법을 제안한다. 제안하는 추출 기법에서는 각 영상의 히스토그램을 비교 및 분석하여 하나의 video을 다수의 구간으로 분할하고, 각 구간의 대표 Thumbnail을 추출하는 방법을 사용한다. 다양한 영상을 이용한 실험 결과는 제안하는 알고리즘이 효과적으로 Thumbnail을 추출함을 보여준다.

• KSCI Review
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• v.15 no.1
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• pp.203-207
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• 2007

본 논문에서는 비디오의 분할을 위하여 먼저 기존에 제안되었던 차이 값 추출방법들의 단점들을 극복하고 장점을 최대한 활용할 수 있으며 급진적 장면전환부터 점진적 장면전환까지 모두 예측할 수 있는 강건하고 복합적인 차이 값 추출방법에 대해서 제안한다. 이 방법은 지역적 $X^2$-테스트로서 기존의 컬러 히스토그램과 $X^2$-테스트를 결합한 방법이다. 본 논문을 위하여 기존의 히스토그램 기반 알고리즘과 비교하여 좋은 성능을 보여주는 $X^2$-테스트를 변형하였고, 컬러 값의 세분화 작업에 따른 검출효과를 높이기 위하여 명암도 등급에 따른 가중치를 적용한 지역적 $X^2$-테스트를 이용하였다. 이 방법은 복잡하고 다양한 시세계의 영상 변화를 가장 일반적이고 표준화된 방법으로 분석하고 분할하며 표현할 수 있는 방법이다. 기존의 $X^2$-테스트와 제안된 지역적 $X^2$-테스트 방법의 비교는 실험을 통해 입증되었다.

• Radiation Oncology Journal
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• v.27 no.4
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• pp.240-248
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• 2009

Purpose: To provide a simple research tool that may be used to analyze a dose volume histogram from different radiation therapy planning systems for NTCP (Normal Tissue Complication Probability), OED (Organ Equivalent Dose) and so on. Materials and Metohds: A high-level computing language was chosen to implement Niemierko's EUD, Lyman-Kutcher-Burman model's NTCP, and OED. The requirements for treatment planning analysis were defined and the procedure, using a developed GUI based program, was described with figures. The calculated data, including volume at a dose, dose at a volume, EUD, and NTCP were evaluated by a commercial radiation therapy planning system, Pinnacle (Philips, Madison, WI, USA) for comparison. Results: The volume at a special dose and a dose absorbed in a volume on a dose volume histogram were successfully extracted using DVH data of several radiation planning systems. EUD, NTCP and OED were successfully calculated using DVH data and some required parameters in the literature. Conclusion: A simple DVH analyzer program was developed and has proven to be a useful research tool for radiation therapy.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.376-379
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• 2008

This paper presents an image retrieval algorithm based on feature vector using color of histogram refinement for a faster and more efficient search in the process of content based image retrieval. First, we segment each of R, G, and B images from RGB color image and extract their respective histograms. Secondly, these histograms of individual R, G and B are divided into sixteen of bins each. Finally, we extract the maximum pixel values in each bins' histogram, which are calculated, compared and analyzed, Now, we can perform image retrieval technique using these maximum pixel value. Hence, the proposed algorithm of this paper effectively extracts features by comparing input and database images, making features from R, G and B into a feature vector table, and prove a batter searching performance than the current algorithm that uses histogram matching and ranks, only.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1283-1288
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• 2011

In this paper we collect data concerning sleep environments in a bedroom and analyze the relationship between the collected condition data and sleep. In addition, this paper detects scene changes from the subjects in a sleeping state and presents the physical conditions, reactions during sleep, and physical sensations and stimuli. To detect scene changes in image sequences, we used color histogram for the difference between the preceding frame and the current frame. In addition, to extract the tossing and turning for different situations, the subjects were instructed to enter the level of fatigue, the level of drinking, and the level of stomach emptiness. For the sleep experiment system, we used the H-MOTE2420 Sensor composed of temperature, humidity, and light sensors. This paper is intended to provide the best sleep environment that enhances sleep quality, thus inducing people today to get regular and comfortable sleep.

• Journal of IKEEE
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• v.5 no.2 s.9
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• pp.190-200
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• 2001

This paper is addressed to welding defect feature vector selection and implementation method of welding defect classifier using fuzzy techniques. We compare IAV, zero-crossing number as time domain analysis, power spectrum coefficient as frequency domain, histogram as both domain for welding defect feature selection. We choose histogram as feature vector by graph analysis and find out that maximum frequent occurrence number and section of corresponding signal scale in relative histogram show obvious difference between normal welding and voiding with penetration depth defect. We implement a fuzzy welding defect classifier using these feature vector, test it to verify its effectiveness for 695 welding data frame which consist of 4000 sampled data. As result of test, correct classification rate is 92.96%. Lab experimental results show a effectiveness of fuzzy welding defect classifier using relative histogram for practical Laser welding monitoring system in industry.

• Journal of Digital Contents Society
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• v.19 no.2
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• pp.371-376
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• 2018

In the system security technology, the information hiding field is developed as technologies for embedding information, which are generally used as contents media. The proposed technique is a technical steganography technique which uses a technique of concealing certain information through physical / statistical change of signal values of contents. Recently, there have been various studies based on histogram shifting in reversible data concealment. In multi - peak histogram shifting, the capacity of data concealment gradually increased by applying multiple peak histogram method. In this paper, we analyze the effect of concealment in terms of adopting the histogram shift method including skipping. In addition, we propose multi - branch data concealment as a general method to improve concealment capacity. The above proposal has proved to be an example using mathematical expressions, and further improvement measures could be derived.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.283-293
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• 2002

Purpose : A PC based brachytherapy planning system was developed to display dose distributions on simulation images by 2D isodose curve including the dose profiles, dose-volume histogram and 30 dose distributions. Materials and Methods : Brachytherapy dose planning software was developed especially for the Ir-192 source, which had been developed by KAERI as a substitute for the Co-60 source. The dose computation was achieved by searching for a pre-computed dose matrix which was tabulated as a function of radial and axial distance from a source. In the computation process, the effects of the tissue scattering correction factor and anisotropic dose distributions were included. The computed dose distributions were displayed in 2D film image including the profile dose, 3D isodose curves with wire frame forms and dosevolume histogram. Results : The brachytherapy dose plan was initiated by obtaining source positions on the principal plane of the source axis. The dose distributions in tissue were computed on a $200\times200\;(mm^2)$ plane on which the source axis was located at the center of the plane. The point doses along the longitudinal axis of the source were $4.5\~9.0\%$ smaller than those on the radial axis of the plane, due to the anisotropy created by the cylindrical shape of the source. When compared to manual calculation, the point doses showed $1\~5\%$ discrepancies from the benchmarking plan. The 2D dose distributions of different planes were matched to the same administered isodose level in order to analyze the shape of the optimized dose level. The accumulated dose-volume histogram, displayed as a function of the percentage volume of administered minimum dose level, was used to guide the volume analysis. Conclusion : This study evaluated the developed computerized dose planning system of brachytherapy. The dose distribution was displayed on the coronal, sagittal and axial planes with the dose histogram. The accumulated DVH and 3D dose distributions provided by the developed system may be useful tools for dose analysis in comparison with orthogonal dose planning.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10a
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• pp.1-5
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• 2006

본 논문에서는 유방암의 조기발견에 있어서 중요한 소견중 하나인 군집화된 미세석회질을 유방촬영 영상으로부터 자동으로 분석 및 검출하는 컴퓨터 보조 검출 시스템을 구현하였다. 전처리단계로서 유방영상에 메디안 필터를 사용하여 잡음을 제거하고, 히스토그램과 레이블링 연산을 수행하여 실제 유방영역만을 추출 하는 작업을 구현하였다. 그런 후에 추출된 실제 유방영역에서 LoG (Laplacian of Gaussian)연산을 수행하고 히스토그램을 분석하여 이진화를 수행한후에 후보점을 검출하였다. 마지막으로 이를 이용하여 영역확장 알고리즘을 수행하여 미세석회질의 후보영역을 검출한 후, 미세석회질간의 거리를 분석하여 최종 관심영역을 추출하였다. 데이터베이스는 총 20개의 MIAS Mini Database의 맘모그램 영상을 사용하였으며 실험결과 89%라는 검출 성능을 얻을 수 있었다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1912-1913
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• 2011

본 논문은 공간적분을 이용한 인간 가축 분류를 위한 실시간 영상처리 방법을 제안한다. 입력 영상에 장면 차분 방법을 이용해 차분 영상을 구하고 잡음 제거를 위해 EM 알고리즘을 이용한다. 잡음 제거된 템플릿 영상에 대해 KLT 알고리즘을 이용하여 특징 벡터를 구한다. 추출된 이동 객체의 움직임 벡터 기반으로 히스토그램을 생성한다. SA 알고리즘을 이용하여 히스토그램을 분석 하여, 최종적으로 인간과 가축을 분류한다.