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Brightness Enhancement, Wide Color-Gamut Expansion and Power Consumption Reduction for Improving Color LCD Systems
|關鍵字:||Brightness Enhancement;彩色液晶顯示系統;Wide Color-Gamut Expansion;Power Consumption Reduction;Color LCD Systems;亮度增強;色域擴張;功率改善||出版社:||電機工程學系所||引用:|| B. W. Lee, C. Park, S. Kim, T. Kim, Y. Yang, J. Oh, J. Choi, M. Hong, D. Sakong, K. Chung, “TFT-LCD with RGBW Color System,” SID2003 Digest of Technical Papers, pp. 1212-1215, 2003.  B. W. Lee, K. Song, Y. Yang, C. Park, J. Oh, C. Chai, J. Choi, N. Roh, M. Hong, K. Chung, “Implementation of RGBW Color System in TFT-LCDs,” SID2004 Digest of Technical Papers, pp. 111-113, 2004.  A. D. Arnold, T. K. Hatwar, M. V. Hettel, P. J. Kane, M. E. Miller, M. J. Murdoch, J. P. Spindler and S. A. Van Slyke, “Full-Color AMOLED with RGBW Pixel Pattern,” Proceedings of the 24th International Display Research Conference, pp. 252-255, 2004.  H. J. Yoon, J. H. Lee, K. P. Hong, J. Y. Chun, B. Y. Ryu, J. M. Jun and J. Y. Lee, “Development of the RGBW TFT-LCD with Data Rendering Innovation Matrix(SRIM),” SID2005 Digest of Technical Papers, pp.244-247, 2005.  C. Y. Tsai, Y. C. Tsai, Y. J. Chang, W. C. Chang and D. L.P. Ting, “Advanced Transmissive-LCDs with High Reflectance in RGBW,” Proceeding of the 13th International Display Workshops, pp.809-810, 2006. C. H. B Elliott, “Reducing Pixel Count without Reducing Image Quality,” Information Display, pp. 14-17, Dec.1999. C. H. B Elliott, “Active Matrix Display Layout Optimization for Sub-pixel Image Rendering,” Information Display, pp.185-187, Sep. 2000.  C. H. B Elliott and M. F. Higgins, “New Pixel Layout for PenTile Matrix,” Information Display, pp.115-117, Feb. 2002.  C. Betrisey, J. F. Blinn, B. Dresivic, B. Hill, G. Hitchcock, B. Keely, D. P. Mitchell, J. C. Platt, T. Whitted, “Displaced Filtering for Patterned Displays,” SID2000 Digest of Technical Papers, pp.296-299, May 2000. . T. Benzschawel and W. Howard, “Method of and Apparatus for Displaying a Multicolor Image,” U.S. Patent no. 5341153, Aug. 1994.  C. H. B. Elliott, S. Han, M. H. Im, M. Higgins and P. Higgins, “Co-Optimization of Color AMLCD Sub-pixel Architecture and Rendering algorithms,” SID2002 Digest of Technical Papers, pp.172-175, 2002.  B. Wandell, “Fundamentals of Vision: Behavior, Neuroscience and Computation,” SID1994 Digest of Technical Papers, pp. 10-11, 1994.  M. Murch, “Visual Perception Basics,” SID 1987 Digest of Technical Papers, 1987.  R. Murten, J. Gille, J. Larimer, “Delectability of Reduced Blue-Pixel Count in Project Display,” SID 1993 Digest of Technical Papers, 1993.  M. Johnson, “Apparatus and Method for Additive/subtractive Pixel Arrangement in Color Mosaic Displays,” U.S. Patent no.4886343, Dec. 1989.  R. Sprague, L. Silverstein and R. Bruce, “Two Path Liquid Crystal Light Valve Color Display with Light Coupling Lens Array Disposed along the Re-Green ight Path,” U.S. Patent no. 5315,418, May 1994.  S.T. Lo and R. S. Weng, “Method and apparatus for four-color data converting,” US patent #20060274212, 2006.  S. Roth, N. Weiss, M. B. Chorin, I. B. David and C. H. Chen, “Multi-primary LCD for TV Application,” SID2007 Digest of Technical papers, pp. 34-37, 2007.  Y. C. Yang, K. Song, S. Rho, N. S. Rho, S. J. Kang, K. B. Deul, M. Hong, K. Chung, W. H. Choe, S. Lee, C. Y. Kim, S. H. Lee and H. R. Kim, “Development of Six Primary-Color LCD,” SID2005 Digest of Technical papers, pp. 1210-1213, 2005.  M. Takaya, K. Lto, G. Ohashi and Y. Shimodaira, “Color Conversion Method for Multi Primary Displays in Order to Reduce the Power Consumption and Conversion Time,” 11th International Display Workshops, pp. 1611-1614, 2004.  G. Harbers and C. Hoelen, “High Performance LCD Backlighting using,” SID2001 Digest of Technical papers, pp. 702-705, 2001.  T. Matsumoto, Y. Akiyama, T. Nakatsue, S. Haga, T. Arai, H. Shibata, Y. Kuze, M. Hatanaka and K. Kakinuma, “Displaying sYCC Still Image on a Wide-Color-Gamut Television,” 11th International Display Workshops, pp. 1611-1614, 2004.  C. T. Liu, A. Wang, H. J. Hong, Y. J. Hsieh, M. S. Lai, A. Tsai, T. M. Wang, M. J. Jou, W. C. Chang, S. L. Sui, J. H. Liao and M. F. Tien, “Color and Image Enhancement for large-Size TFT-LCD TVs,” SID2005 Digest of Technical papers, pp. 1730-1733, 2005.  H. H. Cho, J. H. Youn and M. R. Choi, “An Image Enhancement Algorithm for Flat Panel Display,” 11th International Display Workshops, pp. 1591-1594, 2004.  T. Urata, and F. Saitoh, “Adaptive Contrast Improvement Method for Color Image Using Genetic Algorithm,” 10th International Display Workshops, pp. 1519-1521, 2003.  T. L. Wu, C. Y. Ke, C. H. Cheng, C. W. Ho, and Y. W. Huang, “Adaptive Color Image Enhancement Applied to Display Based on Hardware Design,” 13th International Display Workshops, pp. 499-502, 2006.  E. H. Langendijk, and M. A. Klompenhouwer, “More Realistic Colors from Small-Gamut Mobile Displays,” SID2004 Digest of Technical Papers, pp. 1258-1261, 2004.  Patent NO.: US6721000 B1, Title: Adaptive Pixel-evel Color Enhancement for a Digital Camera.  C. C. Lai, C. C. Tsai, J. S. Li, and C. F. Hsu, “Color Gamut and Contrast Enhancement for Mobile Phone Displays,” Proceeding of the 33rd Annual Conference of the IEEE Industrial Electronics Society, Taipei, Taiwan, Nov. 5-8, pp.2580-2585, 2007.  H. Chen, J. Sung, T. Ha and Y. Park, “Locally Pixel-Compensated Backlight Dimming for Improving Static Contrast on LED Backlight LCDs,” SID2007 Digest of Technical papers, pp. 1339-1342, 2007.  T. Shirai, S. Shimizukawa, T. Shiga and S. Mikoshiba, “RGB-LED Backlights for LCD-TVs with 0D, 1D, and 2D Adaptive Dimming,” SID2006 Digest of Technical papers, pp. 1520-1523, 2006.  T. Shiga, S. Kuwahara, N. Takeo and S. Mikoshiba, “Adaptive Dimming Technique with Optically Isolated Lamp Groups,” SID2005 Digest of Technical papers, pp. 992-995, 2005.  K. D. Kim, S. H. Baik, M. H. Sohn, J. K. Yoon, E. Y. Oh, and I. J. Chung, “Adaptive Dynamic Image Control for IPS-Mode LCD TV,” SID2004 Digest of Technical papers, pp. 1548-1549, 2004.  N. Takeo, S. Kuwahara, T. Shiga, and S. Mikoshiba, “Application of Adaptive Dimming Technique to a 17-in. LCTV for Reducing Backlight Power,” 11th International Display Workshops, pp. 671-674, 2004.  T. Shiga, and S. Mikoshiba, “Reduction of LCTV Backlight Power and Enhancement of Gray Scale Capability by Using an Adaptive Dimming Technique,” SID2003 Digest of Technical Papers, pp. 1364-1367, 2003.  J. H. Stessen and J. G. R. Mourik, “Algorithm for Contrast Reserve, Backlight Dimming, and Backlight Boosting on LCD,” SID2006 Digest of Technical papers, pp. 1249-1252, 2006.  L. Kerofsky and S. Daly, “Brightness Preservation for LCD Backlight Reduction,” SID2006 Digest of Technical papers, pp. 1242-1245, 2006.  H. Itoh, “Image Display Device and Image Display Method,” US patent # US7053881, 2006.  Y. T. Kim, “Contrast Enhancement Using Brightness Preserving Bi-Histogram Equalization,” IEEE Transactions on Consumer Electronics, Vol. 43, No. 1, pp. 1-8, Feb. 1997,  L.A. Zadeh, “Fuzzy sets,” Information Control, 8, pp. 338-353, 1965.  T. C. Hsu, “A Novel Method for Image Contrast Enhancement: Fuzzy Contrast Correction (FCC) based on Timing Controller,” Proceedings of the 12th International Display Workshop, pp.1859-1862, 2005.  T. C. Hsu, T. M. Lin and Y. C. Chen, “Fuzzy Contrast Correction (FCC) for image Enhancement,” SID2006 Digest of Technical Papers, pp. 303-305, 2006.||摘要:||
本論文的目的是針對彩色液晶顯示系統，探討與研究其亮度增強、色域擴張、功率改善以及提昇畫面品質的方法與實作技術。兩種新的紅、綠、藍、白( RGBW) 結構被提出，用以提高亮度；一雙層磷光粉之發光二極體被當作背光源，達到高色域之目的；一新型的適應性背光調變技術被研發，用以降低整體彩色液晶顯示系統之功率消耗。針對以上四種技術，本文提出各別之影像處理引擎，用以改善畫面品質，並對其特性作詳盡之研究。
一種創新的RGBW彩色濾光片結構改善50 % 的顯示器亮度與模糊法則的映射演算法保持畫面品質。根據人類視覺對藍色顏色較低的辨識能力，將藍色的畫素一半的區域設計為白色畫素來增加亮度，且不降低色彩飽和度與解析度。然後配合模糊法則的映射演算法，輸入因子為白色畫素周圍的紅、綠、藍畫素資料，可得到相對應的白色畫素以得到較佳的影像品質。
雙層磷光粉發光二極體(MPW LED)與一般的白光方光二極體在一樣的消耗功率與亮度底下比較可擴展13% 的顯示器色域，且依照此顯示面板的特性調整一先進的色彩增艷的方法，得到具有色彩飽和度平均45%提昇且一樣色調的影像品質。
This dissertation presents methodologies and techniques for achieving high-quality color LCD systems. The four developed techniques include brightness enhancement using two novel RGBW color filter structures, wide color gamut expansion employing multi-phosphors white (MPW) light-emitting-diodes (LEDs), and power reduction using an adaptive dimming approach. These four techniques are accompanied by their own image processing engines to improve overall image quality.
The first color filter structure, called half-subpixel RGBW (HS-RGBW), is constructed based on the working principle of human vision. On the basis of human vision lower discrimination in blue color, the half sub-pixels of blue color is replaced by white sub-pixels to enhance brightness without loss of their original color saturation and resolution. A fuzzy mapping algorithm using RGB sub-pixel data around white sub-pixels is proposed to obtain better image quality. The HS-RGBW color filter structure together with the fuzzy mapping algorithm is shown to improve 50% brightness of color LCD display systems.
The second RGBW color filter structure is the modified stripe RGBW (MS-RGBW) that keeps the same high resolution and obtains a higher 50% brightness in comparison with conventional RGB color filters. In the MS-RGBW color filter structure, each pixel with three sub-pixels is the same area to that in the conventional RGB stripe color filter and each row shifts two sub-pixels, thereby achieving a low-cost solution with the existing TFT array in any RGB stripe color filter. An image-processing engine is also designed to achieve sharp text image for thin-film-transistor (TFT) LCD with the MS-RGBW color filter. The image-processing engine consists of two new algorithms: RGB-RGBW mapping algorithm and sub-pixel rendering algorithm. The RGB-RGBW mapping algorithm outputs new RGBW image data without distortion in hue and saturation. The sub-pixel rendering algorithm transfers the RGBW data into corresponding ones in a MS-RGBW color filter structure in order to achieve sharp text image.
The proposed MPW LEDs expand 13% of the display color gamut in comparison with conventional white LEDs under the assumption of equal power consumption and brightness. The MPW LEDs can be not only easily applied to any customized LCM without increasing power consumption and reducing brightness, but also effectively used to enlarge the color gamut expansion. In addition, a rich color image processing method obtains a superior image data by showing about 45% saturation enhancement without hue distortion.
The proposed adaptive dimming technique reduces backlight power consumption and enhances image contrast for global backlight applications. This adaptive dimming technique consists of two new algorithms: backlight dimming algorithm and contrast enhancement algorithm. The backlight-dimming algorithm obtains appropriate 0% to 50% backlight power reduction to save 25% backlight power depending on characteristics of the image data. The contrast enhancement algorithm not only reduces the adverse effect of backlight power saving, but also improves 20.75% enhancement of image contrast ratio on the average.
In addition to detailed descriptions of these four techniques, several computer simulations and experimental results are conducted to show the effectiveness and merits of the proposed methods along with their experimental LCD systems. The developed techniques may be of interest to professionals working in the field of color LCD systems and consumer electronics.
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