• Title/Summary/Keyword: 사진 조명 기법

Search Result 15, Processing Time 0.036 seconds

A Study on the Photographic Rubbing by using Photographic Lighting and Digital Techniques (사진 조명 기법과 디지털 기법을 이용한 사진 탁본 연구)

  • Jang, Seon-Phil;Hahn, Sang-June
    • Journal of Conservation Science
    • /
    • v.25 no.4
    • /
    • pp.363-371
    • /
    • 2009
  • This study is purposed to investigate that current rubbing technique could be replaced by the photographic rubbing techniques with the photographic lighting and digital techniques. The lighting technique is based on the "texture description theory" using the electric flash and the intaglio epitaph was emphasized from the observation of the both side because it is purposed to decipher epitaph. The photographs were retouched using the photoshop to emphasize epitaph and the spots from the lichen on the tombstone were softened. Especially, it shows that faint epitaph could be deciphered if the digital techniques could be used practically even though some part of the epitaph was destroyed or peeled. Furthermore, it will help to investigate, protect and restore the cultural properties because it surely makes the recording of the material, weathering, peeling of the tombstone much easier than the current rubbing technique.

  • PDF

Real-Time Indirect Illumination using a Light Quad-Tree (광원 트리를 사용한 간접 조명의 실시간 렌더링)

  • Ki, Hyun-Woo;Oh, Kyoung-Su
    • Journal of KIISE:Computer Systems and Theory
    • /
    • v.34 no.4
    • /
    • pp.158-167
    • /
    • 2007
  • Indirect illumination plays an important role for realistic image synthesis. We present a novel realtime indirect illumination rendering technique using image pyramids. Hundreds of thousands of indirect point light sources are stored into images, and then they hierarchically clustered into quad-tree image pyramids. We also introduce a GPU based top-down and breadth-first traversal of the quad-trees to approximate the illumination with clusters (set of lights). All steps entirely run on the GPU in real-time. Result images demonstrate that our method represents diffuse interreflection, especially a color bleeding effect well. We achieved interactive frame rates of tens to hundreads, without any preprocessing. We can avoid artifacts caused by sampling, and our method is seven times faster than a recently proposed sampling based method.

The Validity Verifying of Evaluation Object Method Proposal in Subject evaluation experiment for Exterior Lighting (경관조명 주관평가 실험에서의 평가대상 제시 방법에 대한 유효성 검증)

  • 이진숙;유재연;김병수
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.17 no.4
    • /
    • pp.1-7
    • /
    • 2003
  • This is basic study for analyzing the character of the evaluation according to the ways of exterior lighting through the image prediction experiment by computer simulation. The aim of this research is to verify the validity of physical quantity & subjective evaluation on the basis of Online experiment. The following carried out the experiment procedure by conditions of Online experiment, 1) to make a photo of Online experirrent, 2) to measure physical quantity of luminance, and 3) to do subjective evaluation in Online experiment by means of vocabulary of the evaluation through preparation experiment. Then to verify the validity of Online and CG experiment, Online and photo experiment with each subjective evaluation results. The result of this study is that the validity difference is within 5% in the verification the validity of the physic amount, which showed little difference. While in verification of subjective evaluation of online and CG, online and photo experiment, the result is showed little difference as well except a little the item.

A study on Visualization and Enhancement the Latent Fingerprints on Multi-colored Surfaces using the Forensic Light Sources (법광원을 이용한 복잡한 배경의 잠재지문 시각화 및 증강에 관한 연구)

  • Cho, Hyeong-Woo;Koh, Hyun-Seo;Han, Sang-Gyoun;Yu, Je-Seol
    • The Journal of the Korea Contents Association
    • /
    • v.16 no.3
    • /
    • pp.72-80
    • /
    • 2016
  • There are various methods of developing latent fingerprints from evidence found at crime scenes. Crime scene investigators should choose appropriate techniques among them depending on the conditions of the evidences. In this study, we compared the three methods using forensic light sources to develop latent fingerprints on multi-colored surfaces. We selected the various samples according to color, shape and texture of the surfaces and developed the latent fingerprints using fluorescent powder, IR(Infrared) photography and Episcopic Co-axial Illumination. Fluorescent powder was highly effective on all surfaces. IR photography was also effective, but only on the not dark surfaces. Episcopic Co-axial Illumination was effective only on the flat and polished surfaces. Although fluorescent powder was fine regardless of the characteristics of the surfaces, IR photography was better on certain surfaces.

A Study on the Performance Enhancement of Content-based Image Retrieval Systems Using Lighting Directions (빛의 방향을 이용한 내용기반 이미지 검색 시스템의 효율성 향상에 관한 연구)

  • 안재욱;문성빈
    • Proceedings of the Korean Society for Information Management Conference
    • /
    • 2000.08a
    • /
    • pp.113-118
    • /
    • 2000
  • 색상에 의한 내용기반 이미지 검색 기법에 있어서 조명과 관찰자의 환경과 같은 주변 조건을 반영한 시지각 색상 모형은 사진 이미지 속에 나타나는 반사광과 그림자와 같은 영역의 색상 정보를 알 수 없는 것이라고 간주한다는 단점이 있다. 이 연구에서는 그와 같은 알 수 없는 정보를 빛의 방향에 의해 추정하여 검색 시스템의 효율을 향상시키려 하였으며, 검색 실험 결과 이러한 추정 작업과 검색 효율성 향상 사이에는 유의미한 관계가 존재하고 있는 것으로 결론지을 수 있었다.

  • PDF

An Enhancement Technique for Backlit Images using Laplace Pyramid Fusion (라플라스 피라미드 융합을 이용한 역광영상의 개선 방법)

  • Kim, Jin Heon
    • Journal of IKEEE
    • /
    • v.26 no.2
    • /
    • pp.292-298
    • /
    • 2022
  • There is a limit to improving the image quality through global processing of images taken under backlighting because too bright and dark parts are mixed in one scene. This paper introduces a method to improve the quality of a photo by making two virtual images that improve the dark and bright areas of a backlit photo, and fusing them with the original image into a Laplacian pyramid. The proposed method reduces the computational burden by using histogram stretching and gamma transformation that can be simplified with LUT when creating the two virtual images. In addition, in order to obtain a color-enhanced image, contrast conversion was performed only on the luminance using the HSV coordinate system. The proposed technique showed its effectiveness by calculating several NIQA indicators using standard image data sets.

Contrast Enhancement Technique by Intensity Surface Stretching (명도 표면 스트레칭에 의한 화질 개선 기법)

  • Kim, Do-Hyeon;Jung, Ho-Young;Cha, Eui-Young
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.11 no.12
    • /
    • pp.2398-2405
    • /
    • 2007
  • This paper proposes a contrast enhancement technique which stretches the intensity surfaces of image to improve the quality of the digital photos. The proposed method enhances the contrast of image by stretching the intensity surface of the original image to the maximum range of the output image in proportion to the distances between the original intensity surface and upper, lower intensity surface, respectively. The upper and lower intensity surfaces are generated from the original intensity surface by gaussian smoothing. In the experiments, digital color images in a variety of illumination conditions were used and the proposed method was compared with other several existed image enhancement algorithms, which are histogram stretching, surface stretching, histogram equalization, gamma correction and retinex. It was proved that the experimental results were more natural visually without deterioration of gradation.

Image based Shading Techniques for Surfaces with Irregular and Complex Textures Formed by Heterogeneous Materials (이종물질에 의해 복잡한 불규칙 무늬가 형성된 물체 표면의 영상 기반 셰이딩 기법)

  • Lee, Joo-Rim;Nam, Yang-Hee
    • The Journal of the Korea Contents Association
    • /
    • v.10 no.1
    • /
    • pp.1-9
    • /
    • 2010
  • In this paper we present a shading technique for realistic rendering of the surfaces with irregular and complex textures using a single photograph. So far, most works have been using many photographs or special photographing equipment to render the surfaces with irregular and complex textures as well as dividing texture regions manually. We present an automatic selection method of the region segmentation techniques according to properties of materials. As our technique produces a reflectance model and the approximated Bidirectional Reflection Distribution Function(BRDF) parameters, it allows the recovery of the photometric properties of diffuse, specular, isotropic or anisotropic textured objects. Also it make it possible to present several synthetic images with novel lighting conditions and views.

A Study on Mapping 3-D River Boundary Using the Spatial Information Datasets (공간정보를 이용한 3차원 하천 경계선 매핑에 관한 연구)

  • Choung, Yun-Jae;Park, Hyen-Cheol;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.15 no.1
    • /
    • pp.87-98
    • /
    • 2012
  • A river boundary is defined as the intersection between a main stream of a river and the land. Mapping of the river boundary is important for the protection of the properties in river areas, the prevention of flooding and the monitoring of the topographic changes in river areas. However, the utilization of the ground surveying technologies is not efficient for the mapping of the river boundary due to the irregular surfaces of river zones and the dynamic changes of water level of a river stream. Recently, the spatial information data sets such as the airborne LiDAR and aerial images are widely used for coastal mapping due to the acquisition of the topographic information without human accessibility. Due to these advantages, this research proposes a semi-automatic method for mapping of the river boundary using the spatial information data set such as the airborne LiDAR and the aerial photographs. Multiple image processing technologies such as the image segmentation algorithm and the edge detection algorithm are applied for the generation of the 3D river boundary using the aerial photographs and airborne topographic LiDAR data. Check points determined by the experienced expert are used for the measurement of the horizontal and vertical accuracy of the generated 3D river boundary. Statistical results show that the generated river boundary has a high accuracy in horizontal and vertical direction.

A Study on the Performance Enhancement of Content-based Image Retrieval Systems Using Lighting Directions (빛의 방향을 이용한 내용기반 이미지 검색 시스템의 효율성 향상에 관한 연구)

  • 안재욱;문성빈
    • Journal of the Korean Society for information Management
    • /
    • v.17 no.4
    • /
    • pp.157-170
    • /
    • 2000
  • CHROMA. a content-based image rctl-ieval syslem lhas inlroduced a perceptual color modcl, which can siinulatc the visual perceplual process of lhuman beings and eliminate ihe l~roblem ol condilional color variations. Th~s model Ihoweve~ rcgarded shadows and rcllcctions as u n k ~ ~ o u ~ i colors. and took no account of ihe inforclation which can bc gamed from them Th~s ~tudy atlempls Lo estnnale (he unbhown colors using i~ght~ng dil-cclions and lo prove that the process ol unknown colol eslimation can enhance the lperformance o l image retrieval syslems. With the ckperimcntal results, it was concludcd that thc model pmposcd in this study can enhance the perfomancc of content-based image retrieval systems using Lhe ]~ercepiual color model.

  • PDF