多台投影機接合顯示系統之幾何與色彩校正

Geometric and Photometric Calibration for Multi-Projector Displays

廖守鈞(Shou-Chun Liao)

指導教授 ： 洪一平

國立臺灣大學/電機資訊學院/資訊工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.01690

摘要

在這篇論文中，我們提出一套幾何與色彩校正方法來解決建構多台投影機接合之顯示器時所遇到的問題，特別是在色彩這方面。之前的方法大多是利用色域匹配或是只做亮度平衡而忽略色度差異問題。在此我們提出兩階段式色彩校正方法，其不僅可以達到色度一致，並且就人的視覺觀點來看，亮度也可保持均勻。在第一階段，我們採用了類似於 Stone 所提出的色域匹配方法來校正色度，然而不同之處在於我們的色域匹配方法會盡可能保留住各投影機的最大亮度能力。接下來在第二階段我們使用了 Majumder 與 Steven 所提的以人類視覺為基礎的概念來消除亮度差異不均的問題。我們的方法能成功地做到色域匹配與亮度平衡，同時保持高品質的顯像能力。即便利用多台不同廠牌的投影機作接合，透過我們的方法同樣可以達到無接縫的結果。這篇論文所提出的校正方法在許多需要大型且高解析度投影顯示的應用上具有相當的潛力，像是科學視覺化和視覺顯示牆。

關鍵字

多台投影機接合顯示器 ； 幾何校正 ； 色彩校正 ； 色度計 ； 旋轉式可變焦攝影機 ； 高動態範圍圖像

並列摘要

In the thesis I focus on solving the geometric and photometric problems, especially the photometric problem, when building a seamless large display by tiling multiple projectors. Previous work related to photometric calibration mainly addresses either color gamut matching, or luminance balancing while the chrominance variation problem was ignored. Here, a two-phase approach for
photometric calibration is proposed to achieve not only chrominance consistency but also perceptual luminance uniformity across the multi-projector display. In the first phase, we present an approach similar to Stone's work on color gamut matching. Different to Stone's work is that we derive the color gamut of the display based on preserving the maximum luminance for each projector. Afterward,
the second phase eliminates the variance in luminance by using a perceptual method proposed by Majumder and Stevens. However, our method is more efficient because it only needs to generate one luminance attenuation map, rather than deals with each channel separately. The experimental results show that our work successfully deals with both color matching and luminance balancing with high display quality. Even though the tiled display is composed of
projectors of different models, our method can also achieve a seamless result. Our method has great potential for many
applications that require large and high-resolution displays, such as scientific visualizations and visual display walls.

並列關鍵字

Multi-Projector Displays ； Geometric Calibration ； Photometric Calibration ； Colorimeter ； Pan-Tilt-Zoom Camera ； High Dynamic Range Image

參考文獻

[1] L.-W. Chan, W.-S. Ye, S.-C. Liao, Y.-P. Tsai, J. Hsu, and Y.-P. Hung, A °ex-

ible display by intergrating a wall-size display and steerable projectors," The 3rd

[2] Y.-P. Tsai, Y.-N. Wu, and Y.-P. Hung, Generating a multiresolution display by in-

[3] M. Brown, A. Majumder, and R. Yang, Camera-based calibration techniques for

[4] A. Majumder, Properties of color variation across multi-projector displays," Pro-