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Improved characterization method for mobile phone camera and LCD display  

Jang, In-Su (School of Electrical Engineering and Computer Science, Kyungpook National University)
Son, Chang-Hwan (School of Electrical Engineering and Computer Science, Kyungpook National University)
Lee, Cheol-Hee (Major of Computer Engineering, Andong National University)
Song, Kun-Woen (Division of Software Engineering, Uidik University)
Ha, Yeong-Ho (School of Electrical Engineering and Computer Science, Kyungpook National University)
Publication Information
Abstract
The characterization process for the accurate color reproduction in mobile phone with camera and LCD is popular. The camera and LCD characterization, gamut mapping process is necessary to map the camera's input color stimulus, CIEXYZ value, into the LCD's output color stimulus. Each characterization is the process estimating the relation between input and output signals. In case of LCD, because of output device, the output color stimulus for the arbitrary input signal can be measured by spectro-radiometer However, in the camera, as the input device, the characterization is an inaccurate and needs the manual works in the process obtaining the output signal because the input signal can not be generated. Moreover, after gamut mapping process, the noise is increased because the optimized gamma tone curve of camera for the noise is distorted by the characterization. Thus, this paper proposed the system of obtaining the output signal of camera and the method of gamma correction for the noise. The camera's output signal is obtained by RGB values of patches from captured the color chart image. However, besides the illumination, the error for the location of the chart in the viewfinder is generated when many camera modules are captured the chart. The method of correcting the position to correct the error from manual works. The position of camera is estimated by captured image. This process and moving of camera is accomplished repeatedly, and the optimized position can be obtained. Moreover, the lightness curve of camera output is corrected partly to reduce the noise from the characterization process.
Keywords
모바일 폰;특성화;새역사상;감마보정;
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