• Title/Summary/Keyword: white point

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Adaptive White Point Extraction based on Dark Channel Prior for Automatic White Balance

  • Jo, Jieun;Im, Jaehyun;Jang, Jinbeum;Yoo, Yoonjong;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
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    • v.5 no.6
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    • pp.383-389
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    • 2016
  • This paper presents a novel automatic white balance (AWB) algorithm for consumer imaging devices. While existing AWB methods require reference white patches to correct color, the proposed method performs the AWB function using only an input image in two steps: i) white point detection, and ii) color constancy gain computation. Based on the dark channel prior assumption, a white point or region can be accurately extracted, because the intensity of a sufficiently bright achromatic region is higher than that of other regions in all color channels. In order to finally correct the color, the proposed method computes color constancy gain values based on the Y component in the XYZ color space. Experimental results show that the proposed method gives better color-corrected images than recent existing methods. Moreover, the proposed method is suitable for real-time implementation, since it does not need a frame memory for iterative optimization. As a result, it can be applied to various consumer imaging devices, including mobile phone cameras, compact digital cameras, and computational cameras with coded color.

Quadratic polynomial fitting algorithm for peak point detection of white light scanning interferograms (백색광주사간섭무늬의 정점검출을 위한 이차다항식맞춤 알고리즘)

  • 박민철;김승우
    • Korean Journal of Optics and Photonics
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    • v.9 no.4
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    • pp.245-250
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    • 1998
  • A new computational algorithm is presented for the peak point detection of white light interferograms. Assuming the visibility function of white light interferograms as a quadratic polynomial, the peak point is searched so as to minimize the error sum between the measured intensity data and the analytical intensity. As compared with other existing algorithms, this new algorithm requires less computation since the peak point is simply determined with a single step matrix multiplication. In addition, a good robustness is obtained against external random disturbances on measured intensities since the algorithm is based upon least squares principles.

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Properties of the White 5K Au-Ag-In Alloys with Indium Contents (백색 5K Au-Ag-In 합금재의 인듐 첨가량에 따른 물성 변화)

  • Song, Jeongho;Song, Ohsung
    • Korean Journal of Materials Research
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    • v.27 no.7
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    • pp.381-385
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    • 2017
  • In order to replace 14K white gold alloys, the properties of 5K white gold alloys (Au20-Ag80) were investigated by changing the contents of In (0.0-10.0 wt%). Energy dispersive X-ray spectroscopy (EDS) was used to determine the precise content of alloys. Properties of the alloys such as hardness, melting point, color difference, and corrosion resistance were determined using Vickers Hardness test, TGA-DTA, UV-VIS-NIR-colorimetry, and salt-spray tests, respectively. Wetting angle analysis was performed to determine the wettability of the alloys on plaster. The results of the EDS analysis confirmed that the Au-Ag-In alloys had been fabricated with the intended composition. The results of the Vickers hardness test revealed that each Au-Ag-In alloy had higher mechanical hardness than that of 14K white gold. TGA-DTA analysis showed that the melting point decreased with an increase in the In content. In particular, the alloy containing 10.0 wt% In showed a lower melting temperature (> $70^{\circ}C$) than the other alloys, which implied that alloys containing 10.0 wt% In can be used as soldering materials for Au-Ag-In alloys. Color difference analysis also revealed that all the Au-Ag-In alloys showed a color difference of less than 6.51 with respect to 14K white gold, which implied a white metallic color. A 72-h salt-spray test confirmed that the Au-AgIn alloys showed better corrosion resistance than 14K white gold alloys. All Au-Ag-In alloys showed wetting angle similar to that of 14K white gold alloys. It was observed that the 10.0 wt% In alloy had a very small wetting angle, further confirming it as a good soldering material for white metals. Our results show that white 5K Au-Ag-In alloys with appropriate properties might be successful substitutes for 14K white gold alloys.

A STUDY ON THE ROUGHNESS OF THE VISIBLE LIGHT CURED COMPOSITE RESINS (가시광선(可視光線) 중합형(重合型) 복합(複合)레진의 표면조도(表面粗度)에 관(關)한 연구(硏究))

  • Lee, Myung-Jong
    • Restorative Dentistry and Endodontics
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    • v.16 no.2
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    • pp.197-212
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    • 1991
  • The purpose of this study was to roughness on the polished surface of visible light composite resins and was to observe the polished surfaces under Scanning Electrom Microscope(ISI DS 130 AKASHI Co. JAPAN). The surface roughness tester(Surfcom 700A Seimtsu profilometer Tokyo, Japan) was used to measure roughness of polished surfaces. In this study, 5 brands of visible of composite resins were examined, Pyrofile light bond Anterior Lite fil anterior Photo clearfil anterior & posterior Palfique light Anterior and posterior Silux Anterior. White point, Silicure point, Super snap Sof-Lex medium disk as cutting instrument, and celluloid matrix were used. The results obtained were as follows. 1. The Celluloid matrix produced the smoothest surfaces. 2. The surfaces made by Soflex medium disk was smoother than the surfaces made by any other polishing instruments. 3. The values of surface roughness made by White point, Silicon point and Super snap were similer. 4. Palfique light (AP) visible light composite resin showed the smoothest surface after polishing with Silicone point, Super snap disk and Soflex mediuem disk in all tested materials.

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Research of Measurement and Evaluation of White Uniformity Considering Visual Angle on TFT-LCD (TFT-LCD에서 시야각을 고려한 White Uniformity 측정 및 평가에 대한 연구)

  • Chang, Sung-Ho;Seo, Sang-Won
    • Journal of the Ergonomics Society of Korea
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    • v.26 no.4
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    • pp.33-39
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    • 2007
  • In the full white pattern, white uniformity means the degree of uniform distribution of white color and luminance across the whole screen. Among the FPDs(Flat Panel Displays), the TFT-LCD has weak point of viewing angle. The viewing angle considering location and direction can cause different image quality of the TFT-LCD. Therefore, white uniformity of the TFT-LCD must consider viewing angle. Based on international standards, this study proposes an alternative that is realistic and ergonomic measurement of white uniformity of the TFT-LCD.

The Effect of Random Point Excitation on the Vibration Level of Plates

  • Park, Myung-Jin;Yoo, Song-Min;Kim, Chang-Nyung
    • Journal of Mechanical Science and Technology
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    • v.16 no.5
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    • pp.583-590
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    • 2002
  • When a mechanical structure is driven by stationary wide band random point forces, the resulting vibration depends upon the number, location, and joint statistical properties of the exciting forces. In this study, under the assumption of light damping, an approximate procedure for analyzing plates is briefly outlined. The effects of number, location and correlation of the force field on the vibration level are then investigated for various cases in which random point forces with band limited white noise are applied, and the optimal spacing between input forces that produces a relative minimum in the vibration response is predicted.

A STUDY ON THE ROUGHNESS OF THE RESTORATIVE COMPOSITE RESIN (수복용(修複用) 복합(復合)레진의 표면조도(表面粗度)에 관(關)한 연구(硏究))

  • Lee, Myung-Jong
    • Restorative Dentistry and Endodontics
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    • v.13 no.2
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    • pp.207-220
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    • 1988
  • The purpose of this study was to measure roughness on the polished surfaces of composite resin, and was to observe the polished surfaces under Scanning Electron Microscope. The surface roughness tester (Surfcom 700A Semitsu Profilometer Tokyo. Japan) was used to measure roughness of polished surfaces. In this study, 4 brands of composite resin were examined, Pyrofil bond anterior Bell-Feel anterior Clearfil F II and Microrest A.P. White point, Silicone point, Super snap, and Sof-Lex medium disc as cutting instrument, and celluloid matrix were used. The results obtained were as follows. 1) The celluloid matrix produced the smoothest surfaces. 2) Microrest composite resin had smoother surface than any other composite resins after polishing. 3) The values of surface roughness made by White point, Silicon point and Super snap were similar. 4) The surfaces made by Sof-Lex medium disc was smoother than the surfaces made by any other polishing instruments.

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A Tone Compression Model for the Compensation of White Point Shift Generated from HDR Rendering (HDR 렌더링으로 인한 화이트 포인트 이동의 보상을 위한 톤 압축 모델)

  • Chae, Seok-Min;Lee, Sung-Hak;Kwon, Hyuk-Ju;Sohng, Kyu-Ik
    • Journal of Korea Multimedia Society
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    • v.15 no.1
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    • pp.9-17
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    • 2012
  • Recently, a new image appearance model, named iCAM06, was developed for High-Dynamic-Range (HDR) image rendering. The dynamic range of a HDR image needs to be mapped on the range of output devices, which is called the tone reproduction or tone mapping. The iCAM06, the representative HDR rendering algorithm also uses the tone compression using a S-curve mapping function for image reproduction on the dynamic range of output devices. However the iCAM06 occurs white point shift during its tone compression process. Therefore, we propose a compensation method for white point shift problem using the corrected channel gain function. Experiment results show that the proposed method has better performance than the iCAM06.

A case report of Wolff-Parkinson-White syndrome with Hypoxic ischemic encephalopathy (저산소성 허혈성 뇌손상을 받은 WPW증후군 환아 증례 1례)

  • Lee, Jeong-Lim;Kim, Sun-Mi;Ha, Su-Yun;Park, Jun-Beom;Song, In-Sun;Ha, Kwang-Su
    • The Journal of Pediatrics of Korean Medicine
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    • v.19 no.2
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    • pp.127-136
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    • 2005
  • Objective: There were few reports on the treatment of Wolff-Parkinson-White syndrome with Hypoxic ischemic encephalopathy. We treated a Wolff-Parkinson-White syndrome with Hypoxic ischemic encephalopathic patient with Oriental medical approach, and got a significant result. This treatment shows the possibility of healing Wolff-Parkinson-White syndrome with Hypoxic ischemic encephalopathy. So we are reporting this case. Method : Acupuncture treatment, herb medication, rehabilitation therapy were applied for treating patient's chief symptom.(involuntary movement, dystonia, aphasia, fever, perspiration) Results : Consciousness loss in acute stage of Hypoxic ischemic encephalopathy can be considered as Mental Confusion due to Phlegm(Dammisimgyu) in veiw point of Oriental medicine. Wolff-Parkinson-White syndrome can be considered as Sudden Palpitation(Gyounggye) in veiw point of Oriental medicine. After oriental medical treatment, patient's chief symptoms were improved. Conclusion: More study about oriental medical treatment on Wolff-Parkinson-White syndrome with Hypoxic ischemic encephalopathy is needed.

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Design of Mobile Display Color Control Algorithm Using Red and Blue Color Emphasis with Skin Color Protection

  • Ha Joo-Young;Kim Joo-Hyun;Yang Hoon-Gee;Kang Bong-Soon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.3C
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    • pp.264-270
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    • 2006
  • In this paper, we propose the modified display color control system using white point line, boundary lines and S-shaped curves to emphasize blue and red tone colors on CIE1931 diagram. The proposed system divides RGB gamut into movable area and non-movable area by using boundary lines. The colors in movable area are moved into right side or left side along quadratic curve to change the bluish (or reddish) color to more bluish (or more reddish), while those in non-movable area are excepted from color control to prevent skin color from changing. The loci of the quadratic curves are very similar to the arc of the white-point line which connects all points that represent the chromaticities of a black body radiator at different temperatures and is also called the black body locus. The RGB gamut extension by movement of chromaticity coordinate can improve color reproducibility. Therefore in the case of application to LCD, the display shows excellent performance because the LCD's color reproducibility is comparatively lower than that of other display systems. The proposed system is also experimentally demonstrated with Xilinx Virtex FPGA XCV2000E- 6BG560 and the TV set.