• 제목/요약/키워드: Photographic images

검색결과 128건 처리시간 0.022초

Digital Watermarking by Rearranging and Modifying DCT Coefficients

  • Lee, Hee sup;Oh, Sang-Heun;Lee, Keun-Young
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2000년도 ITC-CSCC -2
    • /
    • pp.902-905
    • /
    • 2000
  • Because of the rapid growth of Internet and multimedia applications, how to protect IPR (intellectual property rights) has become a critical issue. Is one of the ways to overcome the problem of the protection of IPR. Digital watermarking call be applied to multimedia data, such as digital images, digital video, and digital audio. In this paper, we propose a digital watermarking technique for digital images to authenticate an owner or an image by embedding visually recognizable patterns, such as logos, signatures, or stamps into images In BDCT (block discrete cosine transform) frequency domain. The proposed method sorts the components of an original image twice. At the same time, the method, also, rearranges the components of a watermark twice in order to be more robust, and finally embeds the watermark into the image. From the experimental results, the conjunction of three similarity measurements shows that our proposed method is robust to image cropping, image filtering, and JPEG (the Joint Photographic Experts Group) both subjectively and objectively.

  • PDF

Performance Evaluation of the JPEG DCT-based Progressive and Hierarchical Codings for Medical Image Communication

  • 안창범;이종수
    • 대한의용생체공학회:학술대회논문집
    • /
    • 대한의용생체공학회 1991년도 추계학술대회
    • /
    • pp.48-53
    • /
    • 1991
  • The discrete cosine transform (DCT)-based progressive and hierarchical coding schemes developed by the International Standardization Organization (ISO) Joint Photographic Experts Groups (JPEG) are implemented and evaluated for the application of medical image communication. For a series of head sections of magnetic resonance images, a compression ratio of about 10 is obtained by the algorithm without noticeable image degradation.

  • PDF

인터넷 사진에 나타난 간호사 이미지 (Nurses' Image Portrayed in the Internet Photographs)

  • 박선아;백민정;성민경;장혜지;정민주;허주희
    • 동서간호학연구지
    • /
    • 제24권1호
    • /
    • pp.28-35
    • /
    • 2018
  • Purpose: The purpose of this study was to investigate the image of nurses portrayed in the internet photographs. Methods: A total of 184 photographs were extracted through the Google portal site using a search term, 'nurse'. Based on the findings of previous studies, a content analysis was conducted with three categories: appearance characteristics, photographic scene, and photographic source. Results: The result revealed that in the photos of appearance characteristics, 237 (98.3%) out of 241 nurses had a normal or less frame, 235 (97.5%) were well-groomed, and 103 (42.7%) wore pants. In addition, 51 (21.2%) wore a cap (21.2%) and 12.0% were male. In the photographic scene, 69 (37.5%) portrayed nursing activities and 36 (19.6%) suggestiveness. In the suggestive photos, all of nurses were female (${\chi}^2=7.63$, p=.021) and they were more likely to have small frames (${\chi}^2=48.40$, p<.001) and wear caps (${\chi}^2=113.54$, p<.001) and skirts (${\chi}^2=39.96$, p<.001). Conclusion: This study showed that the photographs of the nurses wearing a cap and expressing the nurse as a sexual object still appeared. There is a need for a systematic image enhancement strategy so that actual images of nurses can be projected on the internet photographs.

기술적 관점에서 바라본 사진사에 대한 고찰 (Historical Meaning through Technological Issues on Photography)

  • 김상기;김유진
    • 한국콘텐츠학회논문지
    • /
    • 제12권10호
    • /
    • pp.93-105
    • /
    • 2012
  • 사진이 발명된 계기에는 과학과 기술이 뿌리 깊게 자리 잡고 있다. 인간의 손이 아닌 기계와 과학적 처리과정을 통해 생성된 이미지는 사실 그대로의 정교한 이미지로만 그치지 않았다. 사진은 대중문화, 예술, 광고, 과학연구 등 정확한 기록성과 사실적 묘사가 필요한 곳이면 어디든지 사용되었으며, 하나의 인류문화로 자리를 잡았다. 그러나 현재 사진교육에서 다루는 사진사는 사진가의 사진성향, 예술적 패러다임의 시대적 변화와 전쟁과 같은 사회적 변화를 중심으로 사진의 흐름을 다루고 있을 뿐 기술적 관점과 같은 다양한 관점에서 바라본 사진사 연구는 부족하다. 본 연구에서는 사진의 과학 기술적 탄생 배경을 중심으로 사진의 기술사를 살펴보았고 중요한 기술적 성취단계에서 사진은 어떤 영향을 받고 변화했는지 각각의 사례를 통해 분석 및 논의하였다. 이러한 관점의 논의는 빠르게 변화하고 있는 현대사진을 이해하는데 도움이 되며 앞으로의 사진 변화를 예측하는데 참고가 될 수 있기에 적지 않은 의미를 가진다. 또한 사진이 기술에 의존적이라는 사실을 이해함으로써 사진전공자들에게 사진기술 및 관련이론을 습득하는 것이 무슨 의미를 가지는지를 깨우쳐 줄 수 있을 것이다.

한국인의 상악 전치부 심미 인지 선호도 및 정상 치은의 형태 분포 (Perception of maxillary anterior esthetics by dental professionals and lay people and topographical tooth-gingiva interface)

  • 안기연;이주연;김성조;최점일
    • Journal of Periodontal and Implant Science
    • /
    • 제36권4호
    • /
    • pp.817-827
    • /
    • 2006
  • Purpose : This study was designed 1) to compare the perception of dental professionals and lay people with respect to minor variations in maxillary anterior tooth size and alignment and their relation to the surrounding soft tissues, and 2) to evaluate the normal tooth-gingiva topographical relationships in periodontally healthy young subjects, Materials and methods : Maxillary anterior teeth were intentionally diagrammed in varying degree of deviation with respect to one of three common anterior esthetic discrepancies including variations in crown length, shape of gingival margin, and length of interproximal contact, 17 images were generated to be preferentially selected by 2 groups consisting of dental professionals and lay people (total of 740). Smiling photographs of 120 dental students who had healthy periodontium were taken and the photographic images were analyzed to be classified as 17 kinds of altered image groups. Results : The results demonstrated noticeable difference between the varying levels of discrepancy. Both group preferred gingival margin of lateral incisor to be 0.5mm lower than that of central incisor. Lay people preferred the gingival margin shape that has 2/9 horizontal component of the crown width, while dental professionals preferred the gingival margin shape that has 1/9 horizontal component of the crown width. Lay people preferred longer length of the interproximal contact (two thirds of the crown length), whereas dental professionals preferred shorter length of the interproximal contact (half of the crown length). Photographic analysis of normal esthetic gingival topography revealed 2/9 horizontal component and short length of the interproximal contact which was of the hybrid nature of the preferences shared by lay people and dental professionals. Conclusion: The results of this study show that dental professionals and lay people demonstrated significant difference in their preference of dental esthetic components, which may then influence the decision making process by dental professionals with respect to designing the anterior esthetic gingival line.

Fast Extraction of Objects of Interest from Images with Low Depth of Field

  • Kim, Chang-Ick;Park, Jung-Woo;Lee, Jae-Ho;Hwang, Jenq-Neng
    • ETRI Journal
    • /
    • 제29권3호
    • /
    • pp.353-362
    • /
    • 2007
  • In this paper, we propose a novel unsupervised video object extraction algorithm for individual images or image sequences with low depth of field (DOF). Low DOF is a popular photographic technique which enables the representation of the photographer's intention by giving a clear focus only on an object of interest (OOI). We first describe a fast and efficient scheme for extracting OOIs from individual low-DOF images and then extend it to deal with image sequences with low DOF in the next part. The basic algorithm unfolds into three modules. In the first module, a higher-order statistics map, which represents the spatial distribution of the high-frequency components, is obtained from an input low-DOF image. The second module locates the block-based OOI for further processing. Using the block-based OOI, the final OOI is obtained with pixel-level accuracy. We also present an algorithm to extend the extraction scheme to image sequences with low DOF. The proposed system does not require any user assistance to determine the initial OOI. This is possible due to the use of low-DOF images. The experimental results indicate that the proposed algorithm can serve as an effective tool for applications, such as 2D to 3D and photo-realistic video scene generation.

  • PDF

Fashion Images of Homosexuality Depicted in Attitudes, FHM, and Arena Since 2000

  • Choi Kyung-Hee
    • International Journal of Costume and Fashion
    • /
    • 제5권1호
    • /
    • pp.26-41
    • /
    • 2005
  • In this study homosexuality as a discourse represented in contemporary fashion magazines is explored in context. The main concerns are the contemporary construction of homosexuality, fashion symbols to identify homosexuals, and relationships between homosexuality and heterosexual masculinity in fashion images today. After elaborating homosexuality conceptualized historically, an analytical framework from Foucault's discursive approach was made up to interpret the fashion spreads since 2000. As a result, as it is assumed that the concept of homosexuality is constructed by historical specificity, homosexual fashion styles are dynamic. So, it should be recognized that they are formed by power relationships with heterosexuality, and other social factors such as class, race, age, and consumer culture and market trends. On the basis of photographic themes and fashion looks homosexual images are classified into 3 kinds of versions, the effeminate trend setter, the masculine athlete or biker, and the neo camp. However, most of contemporary homosexual photographs are not also so conspicuously different from heterosexual ones. Therefore, in the contemporary structure at least from fashion images, homosexuals can be recognized equally with heterosexual people only except for sexual preference. Thus, homosexual fashion also shares a lot of fashionable products with heterosexual one, with often homosexuals' role as trend -setter.

An Image Quality Evaluation Model for Optical Strip Signal-to-Noise Ratio in the Target Area of High Temperature Forgings

  • Ma, Hongtao;Zhao, Yuyang;Feng, Yiran;Lee, Eung-Joo;Tao, Xueheng
    • Journal of Multimedia Information System
    • /
    • 제8권2호
    • /
    • pp.93-100
    • /
    • 2021
  • Under the time-varying temperature, the high-temperature radiation of forgings and the change of reflection characteristics of oxide skin on the surface of forgings lead to the difficulty of obtaining images to truly reflect the geometric characteristics of forgings. It is urgent to study the clear and reliable acquisition method of hot forging feature image under time-varying temperature to meet the requirements of visual measurement of hot geometric parameters of forgings. Based on this, this chapter first puts forward the quality evaluation method of forging feature image, which provides guarantee for the accurate evaluation of feature image quality. Furthermore, the factors that affect the image quality, such as the radiation characteristics of forgings and the photographic characteristics of cameras, are analyzed, and the imaging spectrum which can effectively suppress the radiation intensity of forgings is determined. Finally, aiming at the problem that the quality of image acquisition is difficult to guarantee due to the drastic change of radiation intensity of forgings under time-varying temperature, an image acquisition method based on minimum signal-to-noise ratio (SNR) based laser light intensity adaptation is proposed, which significantly improves the definition of feature light strips in forging images at high temperature, and finally realizes the clear acquisition of feature images of large-scale hot forging under time-varying temperature.

Subtraction법을 이용한 악관절 X-선사진 판독에 관한 연구 (THE STUDY OF THE INTERPRETATION OF THE TMJ RADIOGRAPHY USING SUBTRACTION TECHNIQUE)

  • 라춘화;유동수
    • 치과방사선
    • /
    • 제17권1호
    • /
    • pp.175-181
    • /
    • 1987
  • The purpose of this study is to know the value of the photographic subtraction technic in the transcranial oblique lateral projection of the TMJ. The author examined the transcranial oblique lateral projection radiographs which comprise 50 cases of 32 persons, compared the transcranial oblique lateral projection films and those subtraction films. The following results were obtained. 1) The condyle at closed jaw position had showed a reversed tone image, but the condyle at the opening position had showed a re-reversed ordinary image. Both condyles had showed one subtraction film because radiographic interpretation of TMJ was easy. 2) On 50 cases of subtraction films, 46 cases had showed same radiographic images compared with trascranial oblique lateral projection films. Four cases (3 cases of erosion, 1 cases of sclerosis) had showed additional changes of images so that capability of interpretation was improved.

  • PDF