Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/6927
標題: 增強液晶顯示器之動態影像品質
Enhancement of Motion Image Quality in LCDs
作者: 張慶雲
Chang, Ching-Yun
關鍵字: Histogram;直方圖;Black Frame Insertion;Dynamic Gamma Correction;TFT-LCD;Gamma Curve;插入黑畫面;動態伽瑪修正;薄膜電晶體液晶顯示器;伽瑪曲線
出版社: 電機工程學系所
引用: [1] 戴亞翔,TFT-LCD面板的驅動與設計,五南圖書出版公司,2006年,p.1~260。 [2] 紀國鐘、鄭晃忠,液晶顯示器技術手冊,台灣電子材料與元件協會,2001年,p.3~224。 [3] 經濟部技術處,2003年平面顯示器年鑑,經濟部技術處,2003年,p.17-51~p17-62。 [4] 林傳生,使用VHDL電路設計語言之數位電路設計,儒林圖書有限公司,2001年,p.1-1~14-10。 [5] 謝崇凱,TFT LCD液晶顯示器的驅動原理(一),新電子科技雜誌,2002年10月第199期。 [6] 謝崇凱,TFT LCD液晶顯示器的驅動原理(二),新電子科技雜誌,2002年11月第200期。 [7] 汪芳興,非晶矽薄膜電晶體液晶顯示器驅動積體電路技術,電子月刊,2003年8月號第97期。 [8] 劉漢文,「平面顯示器製造技術專論」課程講義,中興大學,2003年。 [9] 戴亞翔,「顯示電子電路」課程講義,交通大學,2005年。 [10] Baek-woon Lee1, Cheolwoo Park, Sangil Kim, Manbok Jeon, Jun Heo, Dongsik Sagong, Jongseon Kim and Junhyung Souk, “Reducing Gray-Level Response to One Frame: Dynamic Capacitance Compensation”, SID, pp.1260~1263, 2001. [11] K. Kawabe and T. Furuhashi, “New TFT-LCD Driving Method For Improved Moving Picture Quality”, SID, pp.998~1001, 2001. [12] R. H. M. Wubben and G. J. Hekstra, “LCD Overdrive Frame Memory Reduction using Scalable DCT-based Compression”, SID, pp.1348~1351, 2004. [13] Taiichiro Kurita, “Moving Picture Quality Improvement for Hold-type AM-LCDs”, SID, pp.986~989, 2001. [14] Daigo Sasaki, Masao Imai and Hiroshi Hayama, “Motion Picture Simulation for Designing High-Picture-Quality Hold-Type Displays”, SID, pp.926~929, 2002. [15] T. Nose, M. Suzuki, D. Sasaki, M. Imai and H. Hayama, “A Black Stripe Driving Scheme for Displaying Motion Pictures on LCDs”, SID, pp.994~997, 2001. [16] Sunkwang Hong, Jae-Ho Oh, Po-Yun Park, Tae-Sung Kim, and S. S. Kim, “Enhancement of Motion Image Quality in LCDs”, SID, pp.1353~1355, 2004. [17] Tsutomu Furuhashi, Kazuyoshi Kawabe, Jun-ichi Hirakata, Yoshinori Tanaka and Toshihiro Sato, “High Quality TFT-LCD System for Moving Picture”, SID, pp.1284~1287, 2002. [18] Jun-ichi Hirakata, Akira Shingai, Yoshinori Tanaka and Kikuo Ono and Tsutomu Furuhashi, “Super-TFT-LCD for Moving Picture Images with the Blink Backlight System”, SID, pp.990~993, 2001. [19] N. Fisekovic, T. Nauta, H. J. Cornelissen and J. Bruinink, “Improved Motion-Picture Quality of AM-LCDs Using Scanning Backlight”, Asia Display / IDW, pp.1637~1640, 2001. [20] H. Oura, K. Nakanishi, T. Kokogawa, H. Iwanaga, K. Oda, S. Tahata, A. Yuuki, J. Someya and M. yamakawa, “Improved Image Quality of Moving Images on TFT-LCD by FFD(Feedforward Driving) and Sequentially Intermittent Switched Backlighting”, Asia Display / IDW, pp.1779~1780, 2001. [21] M. J. Swain and D. H. Ballard, “Color indexing”, International Journal of Computer Vision, vol. 7, pp.11-32, 1991. [22] Haeng Won Park, Seung Woo Lee, Young Gi Kim, Jong Seon Kim, Byeungwoo Jeon and Jun Souk, “A Novel Method for Image Contrast Enhancement in TFT-LCDs: Dynamic Gamma Control (DGC)”, SID, pp.1343~1345, 2003. [23] SSD1289, “240 RGB x 320 TFT Driver Integrated Power, Gate and Source Driver With RAM”, SOLOMON, p.1~p.60, 2005. [24] HX8218-A , “HX8218-A 960CH TFT LCD Source Driver with Built-in TCON”, HIMAX, p.1~p.48, 2005. [25] HX8615A , “240-Channel TFT Gata Driver”, HIMAX, p.1~p.18, 2004. [26] S3C2410X , “32-BIT RISC MICROPROCESSOR USER''S MANUAL”, SAMSUNG, p.372~p.413, 2003.
摘要: 
隨著多媒體應用的普及,顯示器不再只是單單顯示一個靜態畫面,可顯示彩色動態影像已成為一個基本功能要求。液晶顯示器在觀看動態影像時最大的問題就是運動影像拖尾現象,這是由於顯示器中液晶的反應速度慢及Hold Type的影像控制所引起,目前最直接有效的改善方法就是插入黑畫面技術。而透過適當的Gamma值校正可將不易分辨畫面細節的影像提升其辨識度對動態影像品質有一定的提升。
本文提出一種結合R、G、B灰階統計分佈直方圖影像分析、插入黑畫面(Insert Black Frame)及動態伽瑪修正(Dynamic Gamma Correction)等技術,成為新的動態伽瑪修正技術。本文所提出的新動態Gamma校正架構,會先傳送影像資料至R、G、B Histogram Extraction統計分析並同時將資料儲存於記憶體中,當完成一張影像圖片資料傳送後,經過R、G、B Histogram Extraction統計分析,我們找到較適合此影像圖片的Gamma值,我們會將此結果分別送至R、G、B Look up Table改變其內部的對照表。當影像資料經過這個對照表就會產生另一個新的影像資料傳送至源極驅動IC。如此我們就可以對每張影像圖片做動態 Gamma校正,以此方法將再結合消除拖尾現象的插入黑畫面技術。
一般插入黑畫面的作法,在每個影像畫面後插入一個黑色畫面。而我們利用這種特性略加改變,我們不在影像畫面切換之後才插入黑畫面,我們改在下一個影像畫面資料開始前傳送,當我們正在做灰階分佈直方圖統計分析時,這個時候插入黑畫面,等到我們傳送完一個影像畫面資料且做完適當之Gamma校正後,我們才將顯示器轉為顯示此畫面。此架構可以節省畫面記憶體等硬體電路成本,並得到優異的靜態、動態畫面表現。

Recently, TFT-LCDs have been widely applied by that have several advantages such as thickness and low power consumption. And the diversification has required the TFT-LCDs to be able to display not only the conventional still pictures, but also high-quality motion pictures. It is well known that motion images are blurred when they are displayed on TFT-LCDs. The motion blurred which results from slow response time and the inherent hold-type driving method used in LCDs. One technology might overcome the problem by using black frame insertion between the image frames. To obtain improved motion image quality in LCDs, it is necessary to apply image enhancement technology to TFT-LCDs. Dynamic gamma control can highly improve perceptual image quality such as contrast ratio, brightness.
In this paper, we proposed a novel method for dynamic gamma correction by combining with RGB histogram, dynamic gamma control scheme, and black frame insertion. It was found R, G, B independent the better gamma value by analysis of the R, G, B "gray-level histogram” for each image. Based on the histogram, the "R, G, B Look up Table(LUT)" changes it''s internal synopsis and R, G, B independent gamma control. The dynamic gamma corrects for every image. In addition, the black image insertion without an extra frame memory was proposed to enhance quality of moving pictures.
A conventional way with black image insertion is to insert a black image after every image showed. In our works, the TFT-LCD system showed the black image before every normal image showed. Combined the abovementioned technologies, we analyzed the R, G, B gray-level histogram and according to the results, the optimal gamma correction was performed and then the black image was inserted until the LCDs finished the image data transmission. The proposed TFT-LCD system not only reduces the cost of the hardware, but also achieves high quality still/moving pictures.
URI: http://hdl.handle.net/11455/6927
其他識別: U0005-2508200613052600
Appears in Collections:電機工程學系所

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