色彩調校技術與顯示器構色原理之分析

Analysis of Color Adjustment Technology and Color Construction Theory of Display

廖俊謙(Jiun-Chian Liao)

指導教授 ： 歐陽盟

國立中央大學/理學院/光電科學研究所/碩士(2006年)

摘要

顯示器之色彩表現，是代表一家顯示器廠商技術的重要指標，但
若實際觀察同一條生產線所製造出來的顯示器，因材料、製程、光源等之間的細微差異，導致呈現出來的色彩無法完美匹配，因此顯示器在出廠之前勢必得再做一次校正，由於此時投影機已完全成型，所以調校的工作主要著重在訊號電路區塊。本研究分別建立了LCD電視與前投影顯示器專用的自動量測平台，用來分析顯示器的原始特性，包含Gamma曲線、各種色度單位、色溫等等。同時提出一套演算法，用來計算出上傳至Gamma LUT的數值資料，再加上與顯示器Gamma LUT連接的傳輸介面，完成可以任意設定目標Gamma曲線與色溫點的色彩調校。
根據色彩學混色原理，調校顯示器色溫點必須要犧牲掉部分的亮度，這不是我們所樂見的，因為亮度往往會直接影響到顯示器的價格。本論文就顯示器色溫點位置的選擇，結合色域空間變化與相關色溫的理論，發展出同時兼顧色溫與亮度的演算法，並透過實驗證實在色溫調校準確度不減的情況下，可以增加13.39％的亮度(以LCD投影機為實驗樣本)。
針對不同國家、種族人眼去尋找最適合的色彩表現，是色彩心理學的問題；但如何把預期的色彩完美地呈現在顯示器上，則是我們在工程上需努力的目標。本研究以三種色彩形成方式不同的主流顯示器做為實驗樣本，探討對它們做Gamma曲線與色溫調校的實驗結果並比較其差異性。另外分析由不同因素造成暗場色彩飽和度不足的問題，並深入討論此現象對顯示器色溫的影響。

關鍵字

色溫 ； 顯示器 ； 色彩 ； 構色原理 ； 伽瑪

並列摘要

The color performance of display is the key technical index of the manufacturer. Because of the difference of materials, manufacture, and light sources, the color performance of displays can not match each other perfectly. In this thesis, we constructed a flat-top building for measuring gamma curve, chromaticity, color temperature of liquid-crystal display and projector automatically. In order to adjust the gamma curve and color temperature of displays, we applied an algorithm to calculate the numeral data for uploading to the gamma look-up tables of displays.
According to color mixing theory, the brightness of display will be lost after its color temperature has been changed, and that’s not what we like to see. for this reason, we included the concept of correlated color temperature, trying to find the balance of brightness and chromaticity. Consequently, we proofed that the brightness can raise for percentage of about 13.39% by experiment (LCD projector as sample).
Searching for the prefer color performance of human eyes of various race and nation is psychology, and how to present it on displays is what we have to do. In this thesis, we took three kinds of displays with color consisted in different ways, adjusting their gamma curve and color temperature, and finally comparing the results. In addition, we analyzed why the color saturation decreases in lower gray levels, and discussed the influence on color temperature.

並列關鍵字

gamma ； color temperature ； display ； color construction ； color

參考文獻

[15] Javier Herna´ ndez-Andre´ s, Raymond L. Lee, Jr., and Javier

[1] Mang Ou-Yang, Yi-Ting Kuo, Shi-Wen Huang, Gordon Horng,

[14] Masato Abe, Hiroaki Ikeda, Yasuhiko Higaki, and Matsuroh

Seong-Deok Lee, Yang-Seock Seo, “User-preferred Color

Committee, Gradada, Spain, May 2005.