• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.174-182
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• 2015

In this paper, we developed the small size RGB sensor that recognizes a long distance using a low-cost color sensor. Light receiving portion of the sensor was used as a camera lens for far distance recognition, and illuminating unit was increased the strength of the light by using a high-power white LED and a lens mounted on the reflector. RGB color recognition algorithm consists of the learning process and the realtime recognition process. We obtain a normalized RGB color reference data in the learning process using the specimens painted with target colors, and classifies the three colors using the Mahalanobis distance in recognition process. We apply the developed the RGB color recognition sensor to a prototype of the part classification system and evaluate the performance of its.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.1
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• pp.37-51
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• 2005

The solution way of color difference in display device is using a device profile recorded with color dimension, color properties of each device and is using sRGB color space. The color matching is better sRGB than RGB color space. The sRGB is independent device color space and based on the monitor characteristice. An accurate characterization of the display device is essential for color matching. The calibration and characterization process in display device is needed to transform the device dependent color to the device independent color. The process of characterization performs a linerizaiton and transforms the linearized values into the CIE XYZ tristimulus values. The purposes of this paper is to estimate color reproduction using device profile and to explain the propriety of transformation method using variable.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.3
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• pp.1011-1025
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• 2014

A demosaicing method for a Bayer-like W-RGB color filter array (CFA) is proposed. When reproducing images from a W-RGB CFA, conventional color separation methods for W-RGB CFA are likely to cause blurring near the edges due to rough averaging using a color ratio of neighboring pixels. Moreover, these methods cannot be applied to real-life digital cameras with W-RGB CFA because the methods were proposed under an ideal situation, W=R+G+B, not a real-life situation, $W{\neq}R+G+B$. To improve edge performance, we propose a method of constant color difference assumption with inversed weight, which uses information from all edge directions for interpolating all missing color channels. The proposed method calculates the correlation between W, R, G, and B to enable its application to real-life digital cameras with W-RGB CFA. Simulations were performed to evaluate the proposed method using images captured from a real-life digital camera with W-RGB CFA. Simulation results shows that we can demosaic by using the proposed algorithm compared with the conventional one in about +34.79% SNR, +11.43% PSNR, +1.54% SSIM and 14.02% S-CIELAB error. Thus, the proposed method demosaics better than the conventional methods.

• Journal of Information Display
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• v.11 no.2
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• pp.45-48
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• 2010

A direct-lit liquid crystal display that does not use color filters is proposed. A backlight unit that employs compartmentalized RGB LED and lenticular-lens arrays is used instead of color filters to direct the RGB LED lights into the RGB subpixels. The color-filterless LED backlight design, simulation, and experiment results are presented.

• Journal of the Korean Graphic Arts Communication Society
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• v.27 no.1
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• pp.29-47
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• 2009

Generally, if RGB image is sent to the printer when we print a digital photograph, the printer will convert RGB to CMYK by the inner built-in drive. Because the difference between color domain of RGB and CMYK will cause that change and difference. The most common way to solve the problem is to convert colors by using ICC profile at RIP software or to adapt automatic color converting from the software of the original printer. So we intended to study show which way is most efficient to the digital output and which color mode device is the best based on the printer's own drive in this paper. we tried to observe and check the extended range of color space such as AdobeRGB as well as CMYK and sRGB. Then we made sure which is the suitable color space. Besides, When we convert RGB mode into CMYK mode by utilizing RIP software and adapt the printer's ICC profile made by our selves, we evaluated the output we get and compared the result with extended RGB image. The results are as follows. In case of RGB mode, the printer requests RGB, and that makes the color space more efficient than CMYK's. Converted to CMYK by utilizing RIP software, the chroma is more linearized than the one produced with its' own driver. Compared with sRGB mode's color gamut, AdobeRGB mode's color gamut and CMYK mode's color, CMYK mode's color gamut is the smallest among 3 of them. CMYK mode's color gamut by utilizing RIP software can be changeable. that can be small and narrow or wide and broad. In other words, the volume of color gamut depends on how CMYK is linearized. The color space of sRGB is more advantageous than the one of AdobeRGB in color-reproduction printed. But in the group $-b^*$, the chroma leaves behind in terms of reproduction, In the group of $-a^*$, the chroma is excellent relatively. Visual evaluation of the image, AdobeRGB image has not many reproduction colors. Specially, according to printers' characteristics, Group B of AdobeRGB and sRGB color space is a long way behind In terms of reproduction but Group Y is excellent relatively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5C
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• pp.513-519
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• 2007

Color correlogram is widely used in content-based image retrieval (CBIR) because it extracts not only the color distribution of pixels in images like color histogram, but also extracts the spatial information of pixels in the images. The color correlogram uses single color space. Therefore, the color correlograms does not have robust discriminative features. In this paper, we use both RGB and HSV color spaces together for the color correlogram to achieve better discriminative features. The proposed algorithm is tested on a large database of images and the results are compared with the single color space color correlogram. In simulation results, the proposed algorithm 5.63 average retrieval rank less than single color space correlogram.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11C
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• pp.1040-1048
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• 2009

This paper proposes an auto flesh tone balance algorithm for the picture that is taken for people. General white balance algorithms bring neutral region into focus. But, other objects can be basis if its spectral reflectance is known. In this paper the basis for white balance is human face. For experiment, first, transfer characteristic of image sensor is analyzed and camera output RGB on average face chromaticity under standard illumination is calculated. Second, Output rate for the image is adjusted to make RGB rate for the face photo area taken under unknown illumination RGB rate that is already calculated. Input tri-stimulus XYZ can be calculated from camera output RGB by camera transfer matrix. And input tri-stimulus XYZ is transformed to standard color space (sRGB) using sRGB transfer matrix. For display, RGB data is encoded as eight-bit data after gamma correction. Algorithm is applied to average face color that is light skin color of Macbeth color chart and average color of various face colors that are actually measured.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.2
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• pp.15-28
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• 2007

For the color offset printing, it starts with input of data. The past days, drum scanner or flat scanner used to input of data, but now it changes gradually into using of digital camera because digital camera become popular. The high quality digital camera saves as a data(RAW format), sRGB which have built in digital camera, or Adobe RGB format. sRGB of ICC(International Color Consortium) profile is a standard color gamut of digital camera. Distribution of color gamut in sRGB is less than Adobe RGB have a distribution in ICC profile. sRGB also can not be expressed in some specific part, because distribution of color gamut in sRGB is not able to cover all parts in ICC Profile of international standards CMYK. It is more popular to use Adobe RGB than sRGB to do high quality offset printing and software basis color setting in Europe and Japan. In spite of this data basis, there is a difficulty of doing color correction between the color proofing prints and the final prints. To see how the software color setting effects to RGB data, this thesis will use Gretag Macbeth ColorChecker 24 patch which has the most general natural color chart to compare sRGB and Adobe RGB to check the differences of color changes. It will use the several factors that came out from the process of making ICC Profile to figure out the optimum In-house profile. It also compares the differences of using matt paper and glossy paper to do best quality color proof offset printing, and how the Rendering Intent effects the proof print.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.1049-1054
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• 2011

Color is discerned due to the reflectance of object and its hue is determined by the Ratio of RGB spectrum. The aim of this study is to evaluate the Color information using by the optical system in terms of convenience and simplicity. Firstly, the differential Ratio of RGB is evaluated by photodiode Sensor which achieves a high efficiency with quick tranducer output. To extract the information of RGB Ratio, light emitting diode is built in Color sensing system with photodiode. Our proposed method is very economical, simple, and convenient. Our results can be applied to confirm the accurate information of Color in the research environments and commercial purposes. Thus RGB information can be determined subjectively and thus, the inherent characteristic of Color will be revealed precisely and its related features can be resolved in a real time mode.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.1
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• pp.11-26
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• 2007

In this paper, an experiment was done where the input device used the linear multiple regression and the sRGB color space to perform a color transformation. The output device used the GOG, GOGO and sRGB for the color transformation. After the input device underwent a color transformation, a $3\;{\times}\;20\;size$ matrix was used in a linear multiple regression and the scanner's color representation of scanner was better than a digital still camera's color representation. When using the sRGB color space, the original copy and the output copy had a color difference of 11. Therefore it was more efficient to use the linear multiple regression method than using the sRGB color space. After the input device underwent a color transformation, the additivity of the LCD monitor's R, G and B signal value improved and therefore the error in the linear formula transformation decreased. From this change, the LCD monitor with the GOG model applied to the color transformation became better than LCD monitors with other models applied to the color transformation. Also, the color difference varied more than 11 from the original target in CRT and LCD monitors when a sRGB color transformation was done in restricted conditions.