• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.42 no.6
• /
• pp.111-120
• /
• 2005

A cost effective three-dimensional color gamut mapping architecture is described. The conventional three-dimensional reduced resolution look-up table is considered and the concept of three-dimensional reduced resolution difference look-up table is introduced for cost effective and real-time color gamut mapping. The overall architecture uses one-dimensional memory decomposition of three-dimensional gamut mapping look-up table, three-dimensional interpolation and simple addition operation for generating the final gamut mapped colors. The required computational cost is greatly reduced by look-up table resolution adjustment and further reduced by the gamut mapping rule modification. The proposed architecture greatly reduces the required memory size and hardware complexity compared to the conventional method and it is suitable for real-time applications. The proposed hardware is suitable for FPGA and ASIC implementation and could be applied to the real-time display quality enhancement purposes.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2003.06a
• /
• pp.106-109
• /
• 2003

This paper presents a hue preserving gamut mapping algorithm for color monitor and printer. The gamuts of monitor and printer are set by the profile of color reproduction media, specified by ICC(International Color Consortium) and provided by vendors, then those gamuts are represented on the CIE xy color space. In case that the color of monitor are located on out-of-gamut of printer, these are clipped on the point of gamut boundary of printer towards a reference white point. On the other hand, colors are in-gamut of printer are unchanged. An image generated by the algorithm keeps a ratio of each pixel of original image. Advantages of the algorithm are easy to implement and fast processing time than other algorithms which involve hue preserving especially in CIELAB color space.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.25 no.1
• /
• pp.121-133
• /
• 2007

The CMS(color management system) software was to enable consistent color reproduction from original to reproduction. The CMS was to create RGB monitor and printer characterization profiles and then use the profiles for device independent color transformation. The implemented CMM(color management module) used the CIELAB color space for the profile connection. Various monitor characterization model was evaluated for proper color transformation. To construct output device profile, SLI(sequential linear interpolation) method was used for the color conversion from CMYK device color to device independent CIELAB color space and tetrahedral interpolation method was used for backward transformation. UCR(under color removal) based black generation algorithm was used to construct CIELAB to CMYK LUT(lookup table). When transforming the CIE Lab colour space to CMYK, it was possible to involve the gray revision method regularized in the brightness into colour transformation process and optimize the colour transformation by black generation method based on UCR technique. For soft copy colour proofing, evaluating several monitor specialism methods showed that LUT algorithm was useful. And it was possible to simplify colour gamut mapping by constructing both the look-up table and the colour gamut mapping algorithm to a reference table.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.36S no.1
• /
• pp.38-50
• /
• 1999

Currently many devices reproduce electronic images in the various ways. However the color that is reproduced in any device is different from the original color due to the difference in the gamut between devices. In this paper, an image dependent gamut mapping method is proposed. This method clips the chroma with compensating for the change of lightness caused by the lightness scaling. The anchor point, which is the center point in the mapping, is set as a lower point by the proposed method than a point by the conventional mapping method. This reduces the color difference between point. In addition, to heighten the color contrast on the constant hue, the different two mapping methods are applied to the printer gamut which is divided in two region, bright region and dark region. Consequently, the printer output image was highly consistent with the corresponding monitor image.

• Journal of Korea Spatial Information System Society
• /
• v.4 no.2 s.8
• /
• pp.35-40
• /
• 2002

In this study we developed a CCD camera image capture program for Mobile Mapping System. Especially, two high resolution color images could be captured and saved simultaneously through this program to apply digital photogrammetry. Program developed in this study could be used more effectively on the 3D positioning of road facilities, the state understanding of maintenance and etc. using Mobile Mapping System with GPS-IMU. Most programs currently developed and used are for the panchromatic images. But, newly developed program is for the high resolution color images. Therefore newly developed program could expand application field of Mobile Mapping System widely, and users. This research can improve the usability of 4S' products with stable and reliable.

• Proceedings of the KOSOMBE Conference
• /
• v.1992 no.11
• /
• pp.39-42
• /
• 1992

Color Doppler flow mapping (CDFM) was performed on an $\underline{in\;vitro}$ experimental setup with a regurgitant moving orifice using the proximal isovelocity surface area (PISA) technique. PISA flow rates underestimated actual flow rates by as much as 65%, which is very important in diagnosing patients with valvular regurgitations or stenosis. The correction factor considering the velocity of the orifice improved the PISA flow rates.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.31 no.4
• /
• pp.25-38
• /
• 2003

The main problems of disordered and congested urban landscape are due to the lack of holistic management that can control various elements of forming a city. Especially, the color of urban landscape is problematic because it is related to individual and social characteristics as well as to physical characteristics. Therefore, temporary expedients that can solve only visualized problems can not be a proper solution for color problems of urban landscape. This study originated from the question about why the color of disordered and congested urban landscape has not been improved. This study aims at directly improving the urban environmental color by finding out what the actual problems related to color are, and what the solutions would be. The goal of this study is to find a holistic systematic problem-solving method. Problems of urban environmental color are identified from both literature review and questionnaires to the expert group, such as environmental planning, design group, and the landscape executive group. Through mapping of relationships among these problems, the intellectual map was made to layout the structures of problems. Based on this method, the structures of problems of urban environmental color were classified into 5 categories: 1) the items related to the administrative structure, 2) the items related to the color management goal and system, 3) the items related to the color planning and design phase, 4) the items related to the color consulting committee, and 5) the items related to the present state of color use. Thus, in order to solve the color problem in urban landscape, practical strategy is strongly required. It is not a temporary expedient but a holistic approach. The solution for the problems of urban environmental color could be divided into 6 types; ‘regulations amendment’,‘color standard amendment’,‘color management plan’,‘color education’, and ‘advertisement for the goal of color management’. Regulations amendment among these types was proposed as the most effective method due to the close relationship with problem categories. Thus, as the solution for the problems of urban environmental color, the ‘color management system’ was suggested. Detailed contents the suggested color management system were divided into three parts; 1) legislation by regulations, ordinance and acts, 2) management by controling the level of guidelines, and 3) the standards for execution of this system.

• Journal of Platform Technology
• /
• v.11 no.5
• /
• pp.59-71
• /
• 2023

This paper proposes a method of estimating the illumination chromaticity of a scene in which an image is taken. Storring and Bianco proposed a method of estimating illuminant chromaticity using skin color. Storring et al. used skin color distribution characteristics and black body locus, but there is a problem that the link between the locus and CIE-xy data is reduced. Bianco et al. estimated the illuminant chromaticity by comparing the skin color distribution in standard lighting with the skin color distribution in the input image. This method is difficult to measure and secure as much skin color as possible in various illumination. The proposed method can estimate the illuminant chromaticity for any input image by analyzing the relationship between the skin color information and the illuminant chromaticity. The estimation method is divided into an analysis stage and a test stage, and the data set was classified into an analysis group and a test group and used. Skin chromaticity is calculated by obtaining skin color areas from all input images of the analysis group, respectively. A mapping is obtained by analyzing the correlation between the average set of skin chromaticity and the reference illuminant chromaticity set. The calculated mapping is applied to all input images of the analysis group to estimate the illuminant chromaticity, calculate the error with the reference illuminant chromaticity, and repeat the above process until there is no change in the error to obtain a stable mapping. The obtained mapping is applied to the test group images similar to the analysis stage to estimate the illuminant chromaticity. Since there is no independent data set containing skin area and illuminant reference information, the experimental data set was made using some of the images of the Intel TAU data set. Compared to Finlayson, a similar theory-based existing method, it showed performance improvement of more than 40%, Zhang 11%, and Kim 16%.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.1
• /
• pp.135-143
• /
• 2009

Recently, in the mobile device, the increase of the need for encoding and decoding of high-resolution images requires an efficient implementation of the image codec. This paper proposes a time-optimized color conversion method for the JPEG decoder, which reduces the number of calculations in the color conversion by the rearrangement of arithmetic operations being possible due to the linearity of the IDCT and the color conversion matrices and brings down the time complexity of the color conversion itself by the integer mapping replacing floating-point operations to the optimal fixed-point shift and addition operations, eventually reducing the time complexity of the JPEG decoder. And the proposed method compensates a decline of image quality incurred by the quantification error of the operation arrangement and the integer mapping by using the multi-mode chrominance reconstruction. The performance evaluation performed on the development platform of embedded systems showed that, compared to previous color conversion methods, the proposed method greatly reduces the image decoding time, minimizing the distortion of decoded images.

• Proceedings of the IEEK Conference
• /
• 2002.06d
• /
• pp.255-258
• /
• 2002

Recently, Digital TV viewer have been replacing cathode ray tubes (CRT) with Plasma display panel(PDP). But the chromaticity of the primaries are dependent on RGB input signals. And the colorimetry of PDP changes with gray scale and has a poor performance in color reproduction. In this paper we propose the enhanced algorithm of color reproduction considering nonlinear gamut mapping algorithm. In order to test performance of this algorithm we use the sample colors. As a result of experiments, it was confirmed that the color difference of the digital PDP using the proposed algorithm was considerably reduced.