• 제목/요약/키워드: clear images

검색결과 466건 처리시간 0.027초

에지 방향 히스토그램을 이용한 텍스트 문서 영상의 워터마킹 (A Watermarking for Text Document Images using Edge Direction Histograms)

  • 김영원;오일석
    • 한국정보과학회논문지:소프트웨어및응용
    • /
    • 제31권2호
    • /
    • pp.203-212
    • /
    • 2004
  • 워터마킹은 멀티미디어 컨텐츠의 저작권을 보호하기 위한 방법이다. 이러한 미디어 중에서 텍스트 문서는 블록/줄/단어의 계층 구조와 배경/전경의 확연한 구분 같은 고유한 특성을 나타내므로, 텍스트 문서를 위한 워터마킹 알고리즘은 이러한 특성을 잘 반영하여 설계하여야 한다. 본 논문은 명암을 갖는 텍스트 문서 영상을 위한 워터마킹 알고리즘을 제안한다. 워터마크 신호는 에지 방향 히스토그램을 통해서 삽입된다. 문서 영상의 부분 영상들은 모두 유사한 성질을 갖는다는 ‘부분 영상 일관성’을 제시한다. 한글 영상, 영문 영상, 한문 문서 영상을 대상으로 부분 영상 일관성을 조사하여, 부분 영상 일관성은 언어에 무관하며 다양한 문서 영상에 적용할 수 있음을 보인다. 워터마크 신호를 삽입하기 위하여 에지방향 히스토그램을 조작하였으며 다양한 실험을 통해 알고리즘의 비 인지성과 강인성을 분석하고 평가하였다.

디중분광영상과 LIDAR자료를 이용한 농업지역 토지피복 분류 (Rural Land Cover Classification using Multispectral Image and LIDAR Data)

  • 장재동
    • 대한원격탐사학회지
    • /
    • 제22권2호
    • /
    • pp.101-110
    • /
    • 2006
  • 본 연구에서는 항공 관측으로 얻어진 다중분광영상과 LIDAR (LIght Detection And Ranging) 자료를 이용하여 농업지역의 토지피복 분류 정도를 분석하였다. 다중분광영상은 녹색, 적색, 근적외역의 3분광으로 이루어져 있다. LIDAR 벡터 자료로부터 최초 반사강도 영상과 최초 반사 표고 자료와 최후 반사의 지상 표고 자료의 차이로 산출된 식생 높이 영상이 얻어졌다. 토지피복 분류 방법은 최대우도법을 사용했으며, 다중분광영상의 3밴드 영상 LIDAR의 반사강도 영상, 식생 높이 영상을 이용하였다. 모든 영상을 이용한 토지피복 분류의 전체 정도는 85.6%로 다중분광영상만을 이용한 정도보다 10%이상 향상되었다. 여러 농작물간의 높이의 차이, 수목과 농작물 높이의 차이와 LIDAR 반사강도 차이로 인하여 다중분광영상과 LIDAR 영상을 사용한 토지피복 분류의 정도가 향상되었다.

DETECTION OF DUST LOADED AIRMASS IN SEAWIFS IMAGERY: AN EMPIRICAL DUST INDEX IN COMPARISON WITH MODEL-PREDICTED DUST DISTRIBUTION OVER THE PACIFIC IN APRIL,1998

  • Fukushima, H.;Schmidt, M.;Sohn, B.J.;Toratani, M.;Uno, I.
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
    • /
    • pp.89-94
    • /
    • 1999
  • The paper first proposes an empirical algorithm for detecting dust-loaded airmass observed by Sea Wide Field-of-view Scanner (SeaWiFS). The proposed dust index formula is based on the curvature of the spectral reflectance estimated from the SeaWiFS band 4 (510 nm band) through band 8 (865 nm band) data, assuming "clear ocean water" reflectance. Evaluation of the algorithm is made over several typical Asian dust images including the ones over the Pacific in April, 1998, when a major dust event was reported. The study analyzes the performance and the characteristics of the algorithm by comparing the satellite-derived dust index images with contemporaneous columnar concentration of dust particles predicted by a numerical dust transport model. The comparison reveals several small-scale differences although their dust distribution patterns show good agreement generally.

  • PDF

탄소나노섬유/PVDF-HFP 복합재로 코팅된 부직포의 역학적 및 전기적 특성 변화 (Mechanical and Electrical Properties of Nonwoven Coated with CNFs/PVDF-HFP Composite)

  • 이선희
    • 한국의류산업학회지
    • /
    • 제13권2호
    • /
    • pp.279-284
    • /
    • 2011
  • In this study, the process of preparation nonwoven with coated carbon nano fibers (CNFs) /poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite solution is described. The various contents of CNFs/PVDF-HFP composite coated nonwoven were prepared and characterized by morphological, mechanical, and electrical methods. Nonwovens are coated with CNFs/PVDF-HFP composite solution and decreased the pick up ratio with increasing CNFs contents in range from 0% to 16%. In the results of SEM images, it was clear that the CNFs were evenly distributed in coated nonwoven by SEM images, the existence of CNFs in coated nonwoven was confirmed regularly. The mechanical properties of various contents of CNFs/PVDF-HFP coated nonwoven were examined. The tensile linearity and compression linearity increased with increasing CNFs contents. The electrical properties of the CNFs/PVDF-HFP coated nonwoven increased with increasing CNFs contents.

FUV Images and Physical Properties of the OES region

  • 조영수;민경욱;선광일
    • 천문학회보
    • /
    • 제35권1호
    • /
    • pp.69.2-69.2
    • /
    • 2010
  • The far-ultraviolet (FUV) H2 and C IV emission images and spectra of Orion Eridanus Superbubble (OES) is hereby presented. The OES seems to consists of multiple phase through the detection of highly-ionized gas and pervasive neutral hydrogen. The former is traced by hot gas while the latter is traced by cold medium. A spectral image made with H2 fluorescent emission shows that the spatial distribution of hydrogen molecule is well correlated with the dust map. The model spectra was taken from a photodissociation region (PDR) radiation code which find a best suitable parameter such as hydrogen density, gas temperature and incident uv intensity of the radiation field. C IV emission is caused by intermediate temperature ISM about 10^4.5 K~10^6 K. Therefore we could get more clear evidence to reveal the structure of OES. Feature of spectra for the each sub region is also presented and discussed. The data were obtained with the Far-Ultraviolet Imaging Spectrograph (FIMS) and the whole data handling were followed by previous FIMS analysis.

  • PDF

천수에서의 슬래밍 현상에 대한 실험적 연구 (An Experimental Study on Shallow Water Effect in Slamming)

  • 강효동;오승훈;권순홍
    • 한국해양공학회지
    • /
    • 제23권1호
    • /
    • pp.60-66
    • /
    • 2009
  • This study presents an experimental investigation of the shallow water impact of a box type structure. The analysis was done based on the video images captured by a high speed camera, the flow field obtained by PIV (Particle Image Velocimetry), and pressure measurements in the divided region. The video images showed quite good agreement with the description given by Korobkin. The PIV measurements of the velocity field provided a clear view of the flow pattern for all three stages. The pressure was measured at the bottom of the tank with strain gauge type pressure gauges. The pressure measurements showed the characteristics of divided regions.

파노라마 X선사진상의 무명선에 관한 연구 II (A RADIOGRAPHIC STUDY OF THE PANORAMIC INNOMINATE LINE II)

  • 최갑식;이강숙
    • 치과방사선
    • /
    • 제25권1호
    • /
    • pp.109-114
    • /
    • 1995
  • The purpose of this study was to investigate the changes of the shape of the panoramic innominate line and also to examine the relation of the panoramic innominate line to maxillary posterior wall according to positional changes in panoramic radiographs of the patients who had no pathoses in the maxillary sinus and adjacent bony structures. Thus these panoramic radiographs were obtained and evaluated in standard, forward 10mm, backward 10mm, chin down 10°, and chin up 10° positions. And the following results were obtained : 1. Panoramic innominate lines were not changed in shape according to various positional changes in panoramic radiography. 2. The panoramic innominate line was observed to be more clear images and decreased distance to the posterior wall of maxillary sinus at forward 10mm and chin down 10° positions. And the panoramic innominate line was observed more blurred images and increased distance to the posterior wall of maxillary sinus at backward 10mm and chin up 10° positions.

  • PDF

전하분할 방식의 건조 지문이미지 보상회로 설계 (Circuit Design for Compesation of a Dry Fingerprint Image Quality on Charge Sharing Scheme)

  • 정승민;여협구
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2013년도 춘계학술대회
    • /
    • pp.795-797
    • /
    • 2013
  • 본 논문에서는 지문센서 칩에서 추출된 건조한 지문이미지의 질을 향상시키기 위한 전하분할 방식의 용량성 회로를 제안하고 있다. 건조지문에서 지문표면의 저항이 크므로 이미지의 질에 저하를 가져온다. 건조지문에서 양질의 이미지를 획득하기 위해 수정된 회로가 제안되어 있고 이 회로는 센서표면에서 전하를 제어하기 위한 부가적인 센서플레이트를 적용하고 있다. 제안된 회로는 0.35마이크론 표준 CMOS 공정에서 검증되었다.

  • PDF

TEMPORAL VARIATIONS OF NO2 DISTRIBUTION OVER AN URBAN AREA MEASURED BY IMAGING DIFFERENTIAL OPTICAL ABSORPTION SPECTROSCOPY

  • Lee, Han-Lim
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
    • /
    • pp.302-305
    • /
    • 2007
  • During the CareBeijing campaign in September 2006, Imaging Differential Optical Absorption Spectroscopy (IDOAS) measurements were made over the city of Beijing, China using a spatial resolution of 146 pixels horizontally and 61 pixels vertically, each with a field of view of $0.133^{\circ}$ and $0.072^{\circ}$ in the horizontal and vertical directions, respectively. Using Fraunhofer reference spectra (FRS) for the evaluation of data for two consecutive days, the diurnal variation of $NO_2$ distributions was determined from data measured every single hour from 08:00 until 16:00 on September 9 and 10. Both days presented a fairly clear sky with high visibility. The setup allowed detailed images of the low surface $NO_2$ distribution over Beijing. Images with less than a 30-min temporal resolution showed variation of plume dispersal in both horizontal and vertical directions. An in-situ measurement was also conducted. Results from both instruments are interpreted by considering local emission sources and wind conditions.

  • PDF

환자의 안전을 위한 입식 X선 촬영 보조기구 개발 및 유용성 평가 (The Development of Assistant Device for the Standing X-ray Views and Its Usability for the Patient Safety)

  • 길종원;김용권
    • 대한안전경영과학회지
    • /
    • 제17권4호
    • /
    • pp.223-229
    • /
    • 2015
  • In this study, We designed and implemented a assistant device for the standing X-ray views which is the one of the clinical X-ray imaging position. To evaluate the usability of the proposed assistant device, We choose 11 clinical patient postures that are used frequently and applied the postures to 5 volunteers. 11 images was taken from a volunteer for the patient postures. And we conducted a survey on safety and clinical usefulness, the 5 volunteers responded to the safety and 5 experts responded to the clinical usefulness. The survey results show that the volunteers feel more safe and the obtained images are very clear and clinically useful. The result for the image quality is 4.69 of 5(best) and safety is 2.84 of 3(best). It will be very profitable to both patients and hospitals by using the proposed assistant device.