手寫輸入裝置之取樣模組的設計與實作

Abstract

圖形化介面(Graphic user interface)是目前流行的操作介面之一，而指向裝置(Pointing device)與點擊式操作是圖形化介面的特色。在指向裝置的種類裡，數位板和互動式電子白板等設備都是以手寫輸入。因為手寫輸入的操作方式類似於紙筆繪圖的習慣，常被用於電腦繪圖等領域。 在Windows平台上，大部分的手寫式輸入裝置由廠商提供驅動程式將輸入事件轉換為原有的滑鼠訊息，使其可相容於一般應用程式。繪圖程式以原有的以原有的滑鼠訊息機制取得輸入事件時，因為滑鼠訊息機制是以佇列方式處理滑鼠訊息，佇列處理的時間會影響程式由接收輸入事件與回饋視覺效果的間隔時間。因此干擾程式回應使用者的視覺回饋效果，而影響需要快速視覺回饋的操作行為，如書寫或手繪等。 本研究實作了以Windows Hook為基礎的滑鼠取樣模組，並以非佇列式訊息轉換原本系統發送的滑鼠訊息，以加強繪圖程式使用手寫式輸入裝置的視覺回饋效果。最後進行實驗比較原有滑鼠訊息和本論文設計的效能差異，以驗證本論文的設計確實改善了其效果。

One of the popular user interface, graphic user interface (GUI), is a point device characterized by its "point-and-click" interaction. Among all of the pointing devices, tablets and interactive whiteboards are handwriting equipment. Because using handwriting equipments are similar to drawing with pens and papers, these devices are becoming more prevalent. Furthermore, the visual feedbacks of these devices highly depend on the sampling techniques. Therefore, in this study, we design and implement a sampling module to improve the quality of the visual feedbacks for window-based handwriting devices. In the Windows operating system, manufacturers of the handwriting devices provide drivers to convert input events into mouse messages, so that the device is compatible with the drawing application. The mouse message system employs a queue for messaging and the queuing delay affects the duration between the input event and the visual feedback, and thus, the user's visual feedback. Therefore, the queuing delay will interfere with real-time activities, such as handwriting and drawing, which require rapid visual feedbacks. In this study, we implemented the mouse sampling module using Windows Hook, and converted mouse messages to input events by a non-queue messaging mechanism, to enhance visual feedbacks of the drawing program with the handwriting devices. We compared the efficiencies of the mouse queue mechanism and the design of this study. We found that our design improved the performance of the handwriting devices significantly.