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研究生:游得一
研究生(外文):De-I Yu
論文名稱:基於人類視覺系統運用影像亮度訊號的變化動態調整液晶電視背光亮度
論文名稱(外文):Dynamic Backlight Luminance Adjustment of LCD TV with HVS-Based Video Luma Signal Variance
指導教授:陳念波
學位類別:碩士
校院名稱:元智大學
系所名稱:電機工程學系
學門:工程學門
學類:電資工程學類
論文種類:學術論文
論文出版年:2009
畢業學年度:97
語文別:英文
論文頁數:78
中文關鍵詞:液晶電視動態對比動態背光人類視覺畫質
外文關鍵詞:LCD TVdynamic contrastdynamic backlightHVSpicture quality
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傳統液晶電視的表面發光源是由一固定、均勻且高亮的背光所構成。但是這種結構造成了在低灰階畫面有比較明顯的漏光。因此,傳統液晶電視在連續的影像上無法表現出最好的動態對比畫質,如畫面景深不夠,無立體感。液晶並非是光線發射材料(非發光型式)。因此,它需要有背光模組(BLU)提供一個能維持整個螢幕有均勻亮度的表面亮度光源。當光線到達眼睛,觸擊了視網膜上的視覺感受器,然後經由神經細胞傳送電子訊號到大腦形成影像。此外,人類視覺系統(HVS)有一個重要的特性就是隨著不同的適應性變化的程度做改變稱為差異閾限(Difference Threshold)或恰可察覺差(Just Noticeable Difference (JND))。動態背光調整就是根據此基礎(JND)來做設計的。本方法採取影像處理技術的統計長方圖(Histogram)來操作。然後我們逐幅畫面計算和平均Histogram的輸入影像亮度值,液晶電視的背光亮度會根據每幅畫面的平均影像亮度值的變化動態調整。
根據本研究結果顯示,和傳統背光模式的液晶電視相比,動態背光模式的全螢幕對比的結果增加了7.38倍。因此,本方法「運用影像亮度訊號的變化動態調整背光」在增加LCD TV的動態對比(特殊場景或畫面的最大亮度除以最小亮度的比值)產生實際效益的效果。就製造上而言,本方法可以達到低成本,無需額外支出購買專用面板(低漏光的面板),且設計容易等需求。符合目前台灣LCD TV OEM/ODM製造廠的生產模式。
A conventional surface light source of LCD TV is composed by a “constant, uniform and high bright backlight”. But this architecture makes light leakage at low grey levels picture more pronounced. For this reason, the conventional LCD TV can’t perform the best picture quality of dynamic contrast ratio in sequence video as like no enough depth of field, no stereognosis in pictures. Liquid crystals are not light-emitting materials (non-luminous type). Thus, it is necessary to have Backlight Unit (BLU) to supply a superficial light source type which can maintain the overall screen in uniform brightness. When light reaches eye, it hits the photoreceptors on the retina, which then send an electrical signal through neurons to the brain where an image is formed. In addition, one of the most important HVS characteristics that changes with different adaptation levels is called Difference Threshold or Just Noticeable Difference (JND) Dynamic Backlight Adjustment was base on this foundation (JND) to be designed. The method was adopted Histogram processing of image process technology. And then we calculated and averaged input video Luma values of histogram frame by frame. Luminance of LCD TV backlight would be adjusting dynamically base on the variance of average video Luma value every frames.
According to results of the research, the full screen contrast ratio of dynamic backlight mode was increased to 7.38 times as compare with conventional backlight mode of LCD TV. Thus, the method “Dynamic backlight Adjustment with video Luma signal variance” had the beneficial effect of increasing the dynamic contrast (the ratio of the maximum luminance to minimum luminance of a particular field or frame) of the LCD TV. For manufacture, the method may achieve requirements, which are low cost, no extra expenditure to purchase special panel (low light leakage panel) and easy design etc. It would satisfy the mode of production of LCD TV OEM/ODM makers presently in Taiwan.
書名頁.......................................i
論文口試委員審定書..........................ii
授權書.....................................iii
摘要........................................iv
ABSTRACT....................................vi
ACKNOWLEDGMENTS...........................viii
TABLE OF CONTENTS............................x
LIST OF FIGURES...........................xiii
LIST OF TABLES.............................xvi
CHAPTER 1 INTRODUCTION.......................1
1.1 Motivation...............................1
1.2 Objective of this study..................2
1.3 Thesis organization......................3
CHAPTER 2 THEORY REVIEW......................4
2.1 Human visual system (HVS)................4
2.1.1 The human eye..........................4
2.1.2 Reflectivity and luminance.............8
2.1.3 Psychophysics..........................9
2.2 TFT-LCD overview........................12
2.2.1 LCD structure.........................12
2.2.2 Backlight unit........................14
CHAPTER 3 METHODS AND EXPERIMENTAL PROCESSES..20
3.1 LCD TV system function block............20
3.2 Video transmission......................22
3.3 Image processing and color space conversion..25
3.3.1 A/D conversion....................... 25
3.3.2 Color space conversion................26
3.4 System software structure...............34
3.4.1 Software algorithm....................35
3.4.2 Operating threshold...................37
3.5 Photometry..............................38
3.6 Methods of measurements.................40
3.6.1 Center of luminance and darkroom contrast ration of full screen measurements....................40
3.6.2 Luminance & contrast of centered box measurements..42
3.7 Material characterization...............44
3.7.1 Display color analyzer CA-210.........44
3.7.2 Video test instrument- Quantum data 881 / 882..46
CHAPTER 4 RESULTS AND DISCUSSION............47
4.1 Procedure of setup before measurement...47
4.1.1 Equipment self calibration............47
4.1.2 Measurement setup.....................47
4.1.3 Darkroom conditions and ambient lighting..49
4.2 Results of full screen measurements.....49
4.2.1 Conventional backlight operation in full white/black pattern.....................................50
4.2.2 Dynamic backlight operation in full white/black pattern.....................................52
4.2.3 Brief discussion......................54
4.3 Results of centered box measurements....55
4.3.1 Conventional backlight operation in centered box pattern.....................................56
4.3.2 Dynamic backlight operation in centered box pattern.....................................60
4.3.3 Brief discussion......................64
4.4 Results of video image..................65
4.4.1 Video image of conventional backlight operation..65
4.4.2 Video image of dynamic backlight operation..66
4.4.3 Brief discussion......................66
4.5 Discussion..............................68
CHAPTER 5 CONCLUSION AND FUTURE DIRECTION...70
5.1 Conclusion..............................70
5.2 Future direction........................71
REFERENCES..................................73
APPENDIX....................................76
A.1 Video format in common use for LCD TV...76
A.2 LCD panel specification.................77
VITA........................................78
[1] Nalliah Raman, Gerben Hekstra, “Dynamic contrast enhancement of liquid crystal displays with backlight modulation”, IEEE International Conference on Consumer Electronics, 2005. ICCE., 2005 Digest of Technical Papers, Jan. 2005, pp. 197-198.
[2] Hanfeng Chen, Junho Sung, Taehyeun Ha, Yungjun Park and Changwan Hong, “Backlight Local Dimming Algorithm for High Contrast LCD-TV”, Proc. of ASID. , 2006, 8-12 Oct, 168.
[3] Twan Maintz, “Digital and Medical Image Processing, Image Processing CourseLiterature”, In University Utrecht, Department of Information and Computing Sciences, Chapter 2, pp.18-21, Chapter 4, pp. 56-65,
http://www.cs.uu.nl/docs/vakken/imgp/
[4] Rafael C.Gonzalez, Richard E. Woods, “Digital Image Processing, Third Edition”, Prentice Hall publishing, Jan. 2008, p36-42, p120-140.
[5] Ali Iranli, Wonbok Lee, and Massoud Pedram,“HVS-Aware Dynamic Backlight Scaling in TFT LCD’s”, IEEE Transactions on Very Large Scale Integration (VLSI) Systems, Vol.14,Issue:10, Oct. 2006, pp.1103-1116.
[6] Fred Nicolls,“Digital Signal Processing Course Literature-HVS”In Department of Electrical Engineering, University of Cape Town, pp1-2,http://www.dip.ee.uct.ac.za/~nicolls/lectures/eee4001f/
[7] AU Optronics Corp. (AUO), “AUO online: Technology, TFT-LCD Introduction”. http://www.auo.com/auoDEV/technology.php?sec=tftIntro&ls=en
[8] Chi Mei optoelectronics.(CMO), “CMO website: Technology ,TFT LCD: What is it”.http://www.cmo.com.tw/opencms/cmo/technology/index.html?__locale=en
[9] DSLCD CO.,Ltd., “DSLCD CO.,Ltd website: Product/Backlight Unit?”, DSLCD CO., Ltd., http://www.dslcd.co.kr/new/ENG/sub2-1.html.
[10] Jee-Gong Chang, Chung-Yi Lin, Chi-Chuan Hwang, Ruey-Jen Yang,“Optical Design and Analysis of LCD Backlight Units Using ASAP”,Optical Engineering magazine, Jun.2003, pp.2-4.
[11] Jae-Eul Yeon, Cha-Kwang Kim, Myung-Sub Jung, Woo-Taek Kim, Kyu-min Cho, Hee-Jun Kim, “Effectiveness of FRFETR MOSFETs for the CCFL inverters in LCD TVs”, IEEE, International Symposium on Power Electronics, Electrical Drives, Automation and Motion, 2008. SPEEDAM 2008. Jun. 2008, pp.1351-1355.
[12] Maxim Integrated Products, Dallas Semiconductor, “Maxim Application note 3513: Design Challenges for Backlighting LCD TVs”, Maxim Integrated Products, Dallas Semiconductor Digital Potentiometers Display Drivers Power-Supply Circuits, Jun 23, 2005, pp.1-9, http://www.maxim-ic.com/appnotes.cfm/appnote_number/3513.
[13] O2Mirco, “OZ9982-Data Sheet”, Ver1.0, Feb.2 2006, pp1.
[14] MediaTek Inc., “MT538X Data sheet” MediaTek Inc., Apr. 3 2007, pp.1-6.
[15] Liu, C.T., “Revolution of the TFT LCD Technology”, IEEE Journal of Display Technology, Vol. 3, Issue: 4, Dec. 2007, pp.342-350.
[16] Keith Jack, “Video Demystified Third Edition, A Handbook for the Digital Engineer”, LLH Technology publishing, Eagle Rock, Feb 2001, pp.6-8, pp.15-19.
[17] Wikimedia Foundation, Inc, “Analog-to-digital converter”, http://en.wikipedia.org/wiki/Analog-to-digital_converter
[18] Tinku Acharya and Ajoy K. Ray, “Image Processing: Principles and Applications”, Wiley-Interscience, May 2005, pp.8, 41, 110-114.
[19] Latha Pillai, “Color Space Converter Application Note: Virtex-II Series”, Xilinx, Inc. April 22, 2001, pp.1-2.
[20] Keith Jack, “YCbCr to RGB Considerations Application Note:An9717”, Intersil Corporation, March 1997, pp.1-2
[21] Ahmed Wathik Naji, Abd Rahman Ramli,Rosaliza Ali, Syed Abdul Rahman, Mohd. Liakot Ali “A Segmentation Algorithm based-on Histogram Equalizer
For Fingerprint Classification System” Second International Conference on Electrical and Computer Engineering ICECE 2002, 26-28 December 2002, pp. 390-393.
[22] VESA “Flat Panel Display Measurements Standard Version 2.0”, Video Electronics Standards Association FPDM Task Group, Jun. 2001, pp.21-46, 87-91, 90-100.
[23] Konica Minolta Sensing, Inc, “CA-210 Display Color Analyzer Instruction manual”, Konica Minolta Sensing, Inc, 2002, pp.33-35, pp.95.
[24] Quantum Data, Inc., “881/882 Video Test Generator, User Guide, Revision A.6”, Quantum Data, Inc. Oct. 2005, pp.2, 40-45.
[25] Wei-Chung Cheng, Yu Hou, Massoud Pedram, “Power minimization in a backlit TFT-LCD display by concurrent brightness and contrast scaling”, IEEE Transactions on Consumer Electronics, Vol. 50, No. 1, Feb. 2004, pp.25-32.
[26] Edward F. Kelley, “Display Measurements for Flat Panel Displays”, Society for Information Display (SID), Jun. 2006, pp.61-67.
[27] Chi Mei optoelectronics.(CMO), “V315B3 - L01 Data Sheet Ver2.1”, CMO, Aug. 2008, pp.8-25.
[28] Yi-Hwa Liu; Shun-Chung Wang; Yi-Feng Luo, “Digital dimming control of CCFL drive system using pulse density modulation technique”, TENCON 2007 - 2007 IEEE Region 10 Conference, Oct. 30 2007-Nov. 2, 2007, pp1-4.
[29] VESA, “VESA and Industry Standards and Guidelines for Computer Display Monitor Timing Version 1.0, Revision 0.8”, Video Electronics Standards Association, Sep. 17 1998.
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