互動式多重解析度顯示系統之投影機校正

Abstract

隨著顯示科技及輸入技術的蓬勃發展，為了在互動式顯示裝置上呈現出更好的視覺效果，許多研究致力於開發大型的高解析度顯示環境，並使用拼接式投影技術以達到經濟效益。基於解析度及成本方面的考量，我們在之前的研究中發展了一個使用背投影的互動式多重解析度桌面顯示系統，簡稱i-m-Top。在多重解析度的顯像概念上，由一台可旋轉式投影機及一台廣角投影機所組成，分別提供使用者局部區域的高解析度投影畫面，而在其他區域則提供較低解析度；在多指觸控方面，利用紅外線攝影機及紅外線照射燈，透過電腦視覺技術進行手指的偵測及追蹤。此顯示系統欲順利運作的前提在於必須先透過幾何校正建立起系統中各輸出/輸入元件(觸控桌面、投影機、紅外線攝影機)彼此之間的對應關係。本研究開發出一套自動化的校正方法:透過一台固定式攝影機的輔助，對投影機所呈現的結構化圖樣(Gray Code Patterns)進行即時的取像，並經由影像處理技術以計算對應關係。相較於之前的手動校正方法，除了大幅度降低校正過程中所耗費的時間及人力外，我們在不使用高精密度相機的環境下依然可以達到相當準確的結果。

Advance in display technology has recently become increasing attention fordesigning an interactive display system. To construct a large-scale and high-resolutiondisplay environment based on multi-projector mosaic has also been importantly to meetthe cost-effective consideration. In our previous work, we had developed a tabletopdisplay system called i-m-Top, which is based on multi-touch and multi-resolutiondisplay technique. In this paper, we proposed a convenient and useful approach toautomatically calibrate the projectors using a color camera, to eliminate both keystoneeffect and misalignment problems. Structured light patterns are used to construct thegeometric relationship between the projectors and the display surface, and thenpre-warp the source images for appearing undistorted result. Experimental resultsdemonstrate that the proposed technique successfully reduces the human-effort andlowers the calibration time of the i-m-Top calibration process.