• Title/Summary/Keyword: Photographic Image

Search Result 169, Processing Time 0.04 seconds

A Study on the Image Effect of Tube Voltage (관전압(管電壓)이 화상(畵像)에 미치는 영향(影響))

  • Kang, Hong-Seok;Kim, Chang-Kyun;Huh, Joon
    • Journal of radiological science and technology
    • /
    • v.3 no.1
    • /
    • pp.49-55
    • /
    • 1980
  • To know the effect of tube voltage to X-ray film image, authors made an experimental study on the exponential value of applied voltage and the effect of scattered ray in photographic contrast, and obtained the results as follows: 1. The exponential value of tube voltage was under the control of the applied voltage, the kinds of screens and grids, and its existence. The range of its value was from 1.03 to 5.3. 2. The efficiency of X-ray production was directly proportional to the applied voltage, and to oftain the same density, the tube current(mAs) was inversely proportional to applied voltage 3. The production of scattered rays was in proportion to the tube voltage, and the photographic contrast was mainly influenced by the scattered rays.

  • PDF

Photographic Color Reproduction Based on Color Variation Characteristics of Digital Camera

  • Kim, Ui-Seong;Lee, Jong-Min;Kim, Yong-Min;Park, Ki-Tae;Moon, Young-Shik
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.5 no.11
    • /
    • pp.2160-2174
    • /
    • 2011
  • In this paper, a new technique for color reproduction based on color variation characteristics of digital camera under a dim light condition is proposed. Generally, photographers should adjust a camera exposure properly for obtaining an image with real color tone of subjects. Thus, in case of taking a picture under a dim light condition, the exposure time of a camera has to be relatively longer than the one under a bright light condition. Although images with real color tone of the subject are obtained, the images may get blurred due to the shaky hands of photographer holding the camera. In order to avoid the blur effect, an input image is captured from a camera set as a short exposure time under a dim light condition. Then we propose a method to reproduce color tone of the dim input image. To this end, color variation characteristics which represent color variations of a digital camera are first extracted by analyzing the Macbeth color checker images taken under various exposure values. Then, a color reproduction is performed by an estimation based on the color variation characteristics. Experimental results have shown that the proposed method has achieved better performance of color reproduction, compared with existing methods.

Development of PKNU3: A small-format, multi-spectral, aerial photographic system

  • Lee Eun-Khung;Choi Chul-Uong;Suh Yong-Cheol
    • Korean Journal of Remote Sensing
    • /
    • v.20 no.5
    • /
    • pp.337-351
    • /
    • 2004
  • Our laboratory originally developed the compact, multi-spectral, automatic aerial photographic system PKNU3 to allow greater flexibility in geological and environmental data collection. We are currently developing the PKNU3 system, which consists of a color-infrared spectral camera capable of simultaneous photography in the visible and near-infrared bands; a thermal infrared camera; two computers, each with an 80-gigabyte memory capacity for storing images; an MPEG board that can compress and transfer data to the computers in real-time; and the capability of using a helicopter platform. Before actual aerial photographic testing of the PKNU3, we experimented with each sensor. We analyzed the lens distortion, the sensitivity of the CCD in each band, and the thermal response of the thermal infrared sensor before the aerial photographing. As of September 2004, the PKNU3 development schedule has reached the second phase of testing. As the result of two aerial photographic tests, R, G, B and IR images were taken simultaneously; and images with an overlap rate of 70% using the automatic 1-s interval data recording time could be obtained by PKNU3. Further study is warranted to enhance the system with the addition of gyroscopic and IMU units. We evaluated the PKNU 3 system as a method of environmental remote sensing by comparing each chlorophyll image derived from PKNU 3 photographs. This appraisement was backed up with existing study that resulted in a modest improvement in the linear fit between the measures of chlorophyll and the RVI, NDVI and SAVI images stem from photographs taken by Duncantech MS 3100 which has same spectral configuration with MS 4000 used in PKNU3 system.

A Grouping Method of Photographic Advertisement Information Based on the Efficient Combination of Features (특징의 효과적 병합에 의한 광고영상정보의 분류 기법)

  • Jeong, Jae-Kyong;Jeon, Byeung-Woo
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.48 no.2
    • /
    • pp.66-77
    • /
    • 2011
  • We propose a framework for grouping photographic advertising images that employs a hierarchical indexing scheme based on efficient feature combinations. The study provides one specific application of effective tools for monitoring photographic advertising information through online and offline channels. Specifically, it develops a preprocessor for advertising image information tracking. We consider both global features that contain general information on the overall image and local features that are based on local image characteristics. The developed local features are invariant under image rotation and scale, the addition of noise, and change in illumination. Thus, they successfully achieve reliable matching between different views of a scene across affine transformations and exhibit high accuracy in the search for matched pairs of identical images. The method works with global features in advance to organize coarse clusters that consist of several image groups among the image data and then executes fine matching with local features within each cluster to construct elaborate clusters that are separated by identical image groups. In order to decrease the computational time, we apply a conventional clustering method to group images together that are similar in their global characteristics in order to overcome the drawback of excessive time for fine matching time by using local features between identical images.

The Photography as Technological Aesthetics (데크놀로지 미학으로서의 사진)

  • Jin, Dong-Sun
    • Journal of Science of Art and Design
    • /
    • v.11
    • /
    • pp.221-249
    • /
    • 2007
  • Today, photography is facing to the crisis of identity and dilemma of ontology from the digital imaging process in the new technology form. It is very important points to say rethinking of the traditional photographic medium, that has changed the way we view the world and ourselves is perhaps an understatement and that photography has transformed our essential understanding of reality. Now, no longer are photographic images regarded as the true automatic recording, innocent evidence and the mirror to the reality. Rather, photography constructs the world for our entertainment, helping to create the comforting illusions by which we live. The recognition that photographs are not constructions and reflections of reality, is the basis for the actual presence within the contemporary photographic world. It is shock. This thesis's aim is to look for the problems of photographic identity and ontological crisis that is controlling and regulating digital photographic imagery, allowing the reproduction of the electronic simulations era. Photography loses its special aesthetic status and becomes no more true information and, exclusively evidence by traditional film and paper that appeared both as a technological accuracy and as a medium-specific aesthetic. The result, photography is facing two crises, one is the photographic ontology(the introduction of computerized digital images) and the other is photographic epistemology(having to do broader changes in ethics, knowledge and culture). Taken together, these crises apparently threaten us with the death of photography, with the 'end' of photography and the culture it sustains. The thesis's meaning is to look into the dilemma of photography's ontology and epistemology, especially, automatical index and digital codes from its origin, meaning, and identity as the technological medium. Thus, in particular, thesis focuses on the analog imagery presence, from the nature in the material world, and the digital imagery presence from the cultural situations in our society. And also thesis's aim is to examine the main issues of the history of photography has been concentrated on the ontological arguments since the discovery of photography in 1839. Photography has never been only one static technology form. Rather, its nearly two centuries of technological development have been marked by numerous, competing of technological innovation and self revolution from the dual aspects. This thesis examines recent account of photography by the analysis of the medium's concept, meaning, identity between film base image and digital base image from the aspects of photographic ontology and epistemology. Thus, the structure of thesis is fairy straightforward to examine what appear to be two opposing view of photographic conditions and ontological situations. Thesis' view contrasts that figure out the value of photography according to its fundamental characteristic as a medium. Also, it seeks a possible solution to the dilemma of photographic ontology through the medium's origin from the early years of the nineteenth century to the raising questions about the different meaning(analog/digital) of photography, now. Finally, this thesis emphasizes and concludes that the photographic ontological crisis reflects to the paradoxical dynamic structure, that unsolved the origins of the medium, itself. Moreover, even photography is not single identity of the photographic ontology, and also can not be understood as having a static identity or singular status from the dynamic field of technologies, practices, and images.

  • PDF

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

  • Ahn, C.B.;Lee, J.S.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1991 no.11
    • /
    • 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

Extraction of Information on Road Cutting Slope using RC Helicopter Photographic Surveying System (무선조정 헬리콥터 사진측량시스템을 이용한 절취사면 정보 추출)

  • 이종출;이영도;김진수;조용재
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
    • /
    • 2004.11a
    • /
    • pp.217-222
    • /
    • 2004
  • In this study, cutting slope's digital image has acquired by using video camera attached at RC helicopter. Resulted RMSE from image processing was approximately x-direction 0.27m, y-direction 0.23m and z-direction 0.35m. Application of these methods makes it convenient that acquisition of digital image about before and after the construction work of road cutting slope. Also systematical cutting slope's information acquisition will be possible by cutting slope's quantitative and qualitative analysis.

  • PDF

A Study on the effect of JPEG recompression with the color image quality (JPEG 재 압축이 컬러 이미지 품질에 미치는 영향에 관한 연구)

  • 이성형;구철회
    • Proceedings of the Korean Printing Society Conference
    • /
    • 2000.04a
    • /
    • pp.17-24
    • /
    • 2000
  • The Joint Photographic Experts Group (JPEG) is a standara still-image compression technique, established by the International for Standardization (ISO) and International Telecommunication Standardization Sector (ITUT). The standard is intended to be utilized in the various kinds of color still imaging systems as a standard color image coding format. Because JPEG is a lossy compression, the decompressed image pixel values are nto the same as values before compression. Image of JPEG compression is often made to JPEG recompression at saving to apply JPEG compression of color image. In general, JPEG is a lossy compression and compression image is predicted to be varied image quality according to recompressed Q-factor. Various distortions of JPEG compression and JPEG recompression has been reported in previous paper. In this paper, we compress four difference color samples (photo image, gradient image, vector drawing image, text image) according to various Q-factor, and then compressed images are recompressed according to various Q-factor once again. As the results, we inspect variation of quality and file size of recompressed color image, and ensure the optimum recompression factor.

A study on the effect of JPEG recompression with the color image quality (JPEG 재압축이 컬러 이미지 품질에 미치는 영향에 관한 연구)

  • 이성형;조가람;구철희
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.18 no.2
    • /
    • pp.55-68
    • /
    • 2000
  • Joint photographic experts group (JPEG) is a standard still-image compression technique, established by the international organization for standardization (ISO) and international telecommunication standardization sector (ITUT). The standard is intended to be utilized in the various kinds of color still imaging systems as a standard color image coding format. Because JPEG is a lossy compression, the decompressed image pixel values are not the same as the value before compression. Various distortions of JPEG compression and JPEG recompression has been reported in various papers. The Image compressed by JPEG is often recompressed by same type compression method in JPEG. In general, JPEG is a lossy compression and the quality of compressed image is predicted that is varied in according to recompression Q-factor. In this paper, four difference color samples(photo image, gradient image, gradient image, vector drawing image, text image) were compressed in according to various Q-factor, and then the compressed images were recompressed according to various Q-factor once again. As the result, this paper evaluate the variation of image quality and file size in JPEG recompression and recommed the optimum recompression factor.

  • PDF