• Title/Summary/Keyword: Chrominance

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An Image Merging Method for Two High Dynamic Range Images of Different Exposure (노출 시간이 다른 두 HDR 영상의 융합 기법)

  • Kim, Jin-Heon
    • Journal of Korea Multimedia Society
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    • v.13 no.4
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    • pp.526-534
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    • 2010
  • This paper describes an algorithm which merges two HDR pictures taken under different exposure time to display on the LDR devices such as LCD or CRT. The proposed method does not generate the radiance map, but directly merges using the weights computed from the input images. The weights are firstly produced on the pixel basis, and then blended with a Gaussian function. This process prevents some possible sparkle noises caused by radical change of the weights and contributes to smooth connection between 2 image informations. The chrominance informations of the images are merged on the weighted averaging scheme using the deviations of RGB average and their differences. The algorithm is characterized by the feature that it represents well the unsaturated area of 2 original images and the connection of the image information is smooth. The proposed method uses only 2 input images and automatically tunes the whole internal process according to them, thus autonomous operation is possible when it is included in HDR cameras which use double shuttering scheme or double sensor cells.

Hardcopy Proof Profiling for the Optimization Of Printing Process (인쇄 공정의 최적화를 위한 하드카피 프루프 프로파일링)

  • Cha, Jae-Young;Cho, Ga-Ram;Koo, Chul-Whoi
    • Journal of the Korean Graphic Arts Communication Society
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    • v.28 no.1
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    • pp.25-42
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    • 2010
  • One of the important roles of worflow is color management. In general, color management technique, which is called CMS(color management system), is a method to solve problems that show different characteristics of color regeneration in output devices, and the characteristics of output devices is created in data file called ICC(International Color Consortium) profile. In addition, ICC profile is used to manage color in workflow, and includes other functions, process management and printing quality management. In domestic printing market, workflow is in the pipeline at rapid speed along with CTP, and use of ICC profile required for color management is also in rapid progress. Therefore, this paper produced optimal ICC profile through experiment from the work of linearizing devices used in each field to color conversion work. Moreover, the paper confirmed how ICC profile will be used in printing field. In the profiling experiment based on hardcopy proofing, photographed copy and chrominance were compared by printing out in proof the image created through application and color conversion with the use of camera profile and proof profile produced in colorimetric method. By evaluating if color is expressed accurately from input to output through colorimetric color conversion experiment as above, the paper intended to propose color management method using optimal profile in printing process.

Automatic Camera Pose Determination from a Single Face Image

  • Wei, Li;Lee, Eung-Joo;Ok, Soo-Yol;Bae, Sung-Ho;Lee, Suk-Hwan;Choo, Young-Yeol;Kwon, Ki-Ryong
    • Journal of Korea Multimedia Society
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    • v.10 no.12
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    • pp.1566-1576
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    • 2007
  • Camera pose information from 2D face image is very important for making virtual 3D face model synchronize with the real face. It is also very important for any other uses such as: human computer interface, 3D object estimation, automatic camera control etc. In this paper, we have presented a camera position determination algorithm from a single 2D face image using the relationship between mouth position information and face region boundary information. Our algorithm first corrects the color bias by a lighting compensation algorithm, then we nonlinearly transformed the image into $YC_bC_r$ color space and use the visible chrominance feature of face in this color space to detect human face region. And then for face candidate, use the nearly reversed relationship information between $C_b\;and\;C_r$ cluster of face feature to detect mouth position. And then we use the geometrical relationship between mouth position information and face region boundary information to determine rotation angles in both x-axis and y-axis of camera position and use the relationship between face region size information and Camera-Face distance information to determine the camera-face distance. Experimental results demonstrate the validity of our algorithm and the correct determination rate is accredited for applying it into practice.

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Color Transfer using Color Contrast Based Templates (색의대비 기반 템플릿을 이용한 색상 변환)

  • Park, Young-Sup;Yoon, Kyung-Hyun;Lee, Eun-Seok
    • Journal of Korea Multimedia Society
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    • v.12 no.5
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    • pp.633-643
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    • 2009
  • We propose a color transfer method that used color contrast based templates to express the visual difference clearly between objects, while remaining the quality of the input image. Our algorithm employs colors of both the input image and template distributed on the $a^{\ast}b^{\ast}$chrominance plane of CIE $L^{\ast}a^{\ast}b^{\ast}$color space. The templates are made by considering the effect of color contrast and have the shape of either a line or a curve represented color distribution of the basic colors based gradation image. These tempates can be modeled on spline curves. We also generate simply new templates with the different basic colors by moving the control points of that curve. The color transfer method using the templates is done through a regressive analysis and color matching. We maintained color coherence of the input image by transforming similarly the color distribution of an input image to the one of templates.

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Material Stability Assessment of Low Oxygen and Heating Treatment (저산소 및 열처리법에 대한 문화재 재질 안정성 평가)

  • Jang, Han Gyeol;Baek, Na Yeon;Kang, Dai Ill
    • Journal of Conservation Science
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    • v.30 no.2
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    • pp.149-156
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    • 2014
  • Low oxygen treatment and heating treatment are used to prevent insects in the field of food science. These eco-friendly control methods can be applied to biological control technique in conservation treatment of organic cultural properties. To evaluate material stability, low-oxygen treatment and low oxygen treatment are applied to wood, pigment, paper and textile that are related to historical wooden buildings. As a result, wood moisture content declined after low oxygen treatment. But decline rate is a little, so it can be expected to turn back original state as time passes. And test result on pigment, paper, textile of chrominance and strength of test materials are stable. But after heating treatment, pigments are separated.

Comparative Study for Hair Protection Effect of Hair Essence Prepared Using Human Hair Keratin

  • Lee, Soonhee;Bae, Giyeon;Park, Doohyun;Kim, Sungnam
    • Journal of Fashion Business
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    • v.17 no.3
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    • pp.48-57
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    • 2013
  • This study was performed to quantitatively and qualitatively estimate the effect of keratin essence on hair protection against physicochemical damage. Damaged hairs were obtained from an early thirty woman who dyed her hair two times and did digital permanent treatment of her hair two times. The damaged hairs were divided into four experimental groups, which are the control hair (CH) group without additional beauty treatment, the damaged hair (DH) group by additional dyeing treatment, basic essence-treated hair (BEH) group, and keratin essence-treated hair (KEH) groups according to the research goal. The protection effect of keratin essence against the physicochemical damage was quantitatively compared by difference of chrominance measured using a color difference meter and qualitatively compared by difference of outer morphological structure images pictured using scanning electron microscopy (SEM). The brightness and yellowish blue color of KEH were relatively lower but the reddish blue color was relatively higher than other groups of test hairs. Cuticle structure of the previously DH was irregularly deformed and more strongly deformed or partially broken by additional dyeing treatment. On the other hand, the gaps between cuticle scales of the DH were reformed by treatment with basic essence and reformed and filled by treatment with keratin essence in comparison with the DH group. Conclusively, the keratin essence was effective to protect hair structure against the structural damage induced by the dyeing-treatment, by which the coloring efficiency is thought to be improved.

A Novel Perceptual No-Reference Video-Quality Measurement With the Histogram Analysis of Luminance and Chrominance (휘도, 색차의 분포도 분석을 이용한 인지적 무기준법 영상 화질 평가방법)

  • Kim, Yo-Han;Sung, Duk-Gu;Han, Jung-Hyun;Shin, Ji-Tae
    • Journal of Broadcast Engineering
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    • v.14 no.2
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    • pp.127-133
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    • 2009
  • With advances in video technology, many researchers are interested in video quality assessment to prove better performance of proposed algorithms. Since human visual system is too complex to be formulated exactly, many researches about video quality assessment are in progressing. No-reference video-quality assessment is suitable for various video streaming services, because of no requested additional data and network capacity to perform quality assessment. In this paper, we propose a novel no-reference video-quality assessment method with the estimation of dynamic range distortion. To measure the performance, we obtain mean opinion score (MOS) data by subject video quality test with the ITU-T P.910 Absolute Category Rating (ACR) method. And, we compare it with proposed algorithm using 363 video sequences. Experimental results show that the proposed algorithm has a higher correlation with obtained MOS.

Chroma Interpolation using High Precision Filter, FIR Filter, Linear Filter (FIR 필터, 선형 필터, 고정밀도 필터를 이용한 색차 보간법)

  • Moon, Kyung-Soo;Kim, Jeong-Pil;Lee, Yung-Lyul
    • Journal of Broadcast Engineering
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    • v.17 no.3
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    • pp.480-490
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    • 2012
  • When interpolating chrominance signal, the H.264/AVC standard uses linear interpolation. In this paper, we suggest more effective method that uses a high precision filter, 6-tap FIR filter, 2-tap linear filter for chroma interpolation. The experimental result shows that the proposed method achieves the BD-Rate decrease without the PSNR decrease compared with Jm11.0kta2.7. The maximum BD-rate improvements on Y component are 1.3%, those of Cb and Cr components are 19.8%, 25.0%, respectively. The average BD-rate improvements on Y component are 0.5%, those of Cb and Cr components are 6.1%, 6.9%, respectively.

Six Color Separation for Reducing Graininess in a Middle Tone Region (중간 계조 영역에서 낟알 무늬 특성을 감소시키기 위한 6색 분리 방법)

  • 손창환;김윤태;조양호;하영호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.6
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    • pp.51-59
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    • 2004
  • This paper proposes an improved six-color separation reducing the graininess in a middle tone region based on the standard deviation of the lightness and chrominance in S-CIELAB space. Graininess is regarded as visual perception for the fluctuation of the lightness of the light cyan and cyan or light magenta and magenta. In the conventional methods, the granularity is extremely heuristic and inaccurate due to the use of the visual examination score. Accordingly, this paper proposes a method to calculate the objective granularity for six color separation. First, we use the lightness, redness-greenness, and yellowness-blueness of the S-CIELAB space reflecting the spatial-color sensitivity of the human and normalize the sum of the three standard deviations. Finally, we apply the proposed granularity to the six color separation after assigning the granularity to the lookup table and obtain the result reducing the graininess in a middle tone region.

Design of Invisible Watermarking for H.264/AVC Video Protection (H.264/AVC 비디오 보호를 위한 비가시적 워터마킹의 설계 및 검증)

  • Park, Hye-Jeong;Choi, Jun-Rim
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.6
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    • pp.74-79
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    • 2008
  • In this paper, we propose and design a new 0.264/AVC watermarking algorithm for protection of copyright by inserting a watermark after quantization. This invisible watermarking algorithm insets a watermark into chrominance components of I frame such that we can avoid degradation of original images. According to test results we could limit image degradation by 1dB, avoid bit rate increment within 2% and increase processing time by only 2%. The IP is designed by Hynix 0.25 micron technology and the maximum operating frequency of 115MHz is achieved. The PSNR of the embedded watermark is about 35dB according to the test result.