指向動作是人類的直覺溝通方式。基於指向有完全的空間相容性，同時指向軌跡也有手勢的意義性等優點，本研究建置一套以兩部相機所發展的「三維指向即時偵測與重現系統」。
指向過程中，眼、手、物體屬三點一線的共線性關係，本研究以機器視覺偵測法，透過三維相機校正、二維頭手區塊偵測、頭手位置追蹤等程序，取得頭手三維的連續移動位置。研究另以大型顯示器重現三維指向軌跡，作為指標之用，系統進而分析軌跡指向的速度與加速度變化，系統的更新速率為20Hz。
為了驗證無穿戴指向手勢的優勢，本研究設計了一套指向手勢辨識邏輯，並利用Finite State Machine將手勢組合與音樂播放介面的功能（播放、暫停、音量控制、曲目更換）配對。驗證結果顯示，下達各手勢指令的時耗平均在4秒以內，正確率則在90%以上。

Pointing gesture is a very intuitive human communication. Basically, the pointing orientation has a fully spatial compatibility, and the meaning of gesture is in the pointing trajectory. The objective of this study is to design and development a "free-hand, 3 dimensional, real time, pointing gesture recognition system” using 2 cameras.
When pointing an object, the eye, the finger, and the object should be collinear. Base upon this principle, sub-system of 3-D camera calibration, hand/head area detection, and/head tracking were developed to continuously tracking the hand/head 3-D positions. The 3-D pointing positions were reconstructed in a large screen with a refresh speed of 20 Hz. It was then the velocity and the accelerations of the pointing trajectories were calculated.
To verify the advantage of the system, we built a remote controlled music player with free-hand comments of play, pause, volume control, move to a previous, and move to the next control. Experiment result showed that the average time-spending for gesture command is less than 4 seconds, and the recognition rate of all comments is more than 90%.

期刊論文
[1] Lawrence R. Rabiner, “A tutorial on Hidden Markov models and selected applications in speech recognition,” Proceedings of IEEE, Vol.77 No.2, 1989.

[2] Michael Isard, Andrew Blake, "CONDENSATION—Conditional Density Propagation for Visual Tracking," International Journal of Computer Vision 29(1), pp: 5-28, 1998.

研討會論文
[3] R. Y. Tsai, “A versatile camera calibration technique for high-accuracy 3D machine vision metrology using off-the-shelf TV cameras and lenses,” IEEE J. Robot. Automat., vol. RA-3, pp. 323–344, 1987.

[4] Byung-Woo Min, Ho-Sub Yoon, Jung Soh, Takeshi Ohashi, Toshiaki Ejima, "Gesture-based editing system for graphic primitives and alphanumeric characters," Engineering Applications of Arti®cial Intelligence 12, pp:429-441, 1999.

[5] Byung-Woo Min, Ho-Sub Yoon, Jung Soh, Takeshi Ohashi, Toshiaki Ejima, "Visual Recognition of Static/Dynamic Gesture: Gesture-Driven Editing System," Journal of Visual Languages and Computing No.10, pp: 291-309, 1999.

[6] Yoichi Sato, Yoshinori Kobayashi, Hideki Koike, "Fast Tracking of Hands and Fingertips in Infrared Images for Augmented Desk Interface," IEEE Automatic Face and Gesture Recognition (FG2000), pp.462-467, 2000.

[7] Ho-Sub Yoon, Jung Soh, Younglae J. Bae, Hyun Seung Yang, "Hand gesture recognition using combined features of location, angle and velocity," Pattern Recognition 34, pp: 1491-1501, 2001.

[8] M.S. Lee, D. Weinshall, E. Cohen-Solal, A. Colmenarez, D. Lyons, "A Computer Vision System for On-screen Item Selection By Finger Pointing," Computer Vision and Pattern Recognition (CVPR 2001), Proceedings of the 2001 IEEE Volume: 1, pp.I-1026- I-1033, 2001.

[9] Chan Wah Ng, Surendra Ranganath, “Real-time gesture recognition system and application,” Image and Vision Computing Volume 20, pp: 993–1007, 2002.

[10] Yoichi Sato, Hideki Koike, "Real-Time Fingertip Tracking and Gesture Recognition," IEEE Computer Graphics and Applications, Volume: 22, Issue. 6, pp: 64-71, 2002.

[11] Dorin Comaniciu, Visvanathan Ramesh, Peter Meer, “Kernel-Based Object Tracking,” IEEE Transactions on Pattern Analysis and Machine Intelligence
Volume 25, pp: 564-575, 2003.

[12] Feng-Sheng Chen, Chih-Ming Fu, Chung-Lin Huang, “Hand gesture recognition using a real-time tracking method and hidden Markov models,” Image and Vision Computing Volume 21, pp: 745–758, 2003.

[13] Carlo Tomasi, Slav Petrov, and Arvind Sastry, "3D Tracking = Classification + Interpolation," Proceedings of the Ninth IEEE International Conference on Computer Vision (ICCV 2003) 2-Volume Set, 2003.

[14] Aditya Ramamoorthy, Namrata Vaswani, Santanu Chaudhury, Subhashis Banerjee, "Recognition of dynamic hand gestures," Pattern Recognition, Volume. 36, pp: 2069-2081, 2003.

[15] C. Keskin, A. Erkan, L. Akarun, "Real Time Hand Tracking and 3D Gesture Recognition for Interactive Interfaces Using HMM" Proceeding of ICANN/ICONIP, pp.567-570, 2003.

[16] Kai Nickel, Rainer Stiefelhagen, "Pointing Gesture Recognition based on 3D-Tracking of Face, Hands and Head Orientation," ICMI’03, November 5-7, 2003, Vancouver, British Columbia, Canada.

[17] Akihiro Imai, Nobutaka Shimada, Yoshiaki Shirai, “3-D Hand Posture Recognition by Training Contour Variation,” Proceedings of the Sixth IEEE International Conference on Automatic Face and Gesture Recognition (FGR’04), 2004.

[18] McKenna S J and Morrison K, "A Comparison of Skin History and Trajectory-based Representation Schemes for the Recognition of User-Specified Gestures", Pattern Recognition 37(5), pp: 999-1009, 2004.

[19] Yu Yamamoto, Ikushi Yoda, and Katsuhiko Sakaue, "Arm-pointing Gesture Interface Using Surrounded Stereo Cameras System," Pattern Recognition, 2004. ICPR 2004. Proceedings of the 17th International Conference on, Volume: 4, pp. 965 - 970, 2004.

[20] Roland Kehl and Luc Van Gool, "Real-Time Pointing Gesture Recognition for an Immersive Environment," Automatic Face and Gesture Recognition, 2004. Proceedings. Sixth IEEE International Conference on, pp.577-582, 2004.

[21] Kai Nickel, Edgar Seemann, Rainer Stiefelhagen, "3D-Tracking of Head and Hands for Pointing Gesture Recognition in a Human-Robot Interaction Scenario," Automatic Face and Gesture Recognition, 2004. Proceedings. Sixth IEEE International Conference on, pp.565-570, 2004.

碩士論文

[22] 陳永祚，「虛擬環境下即時三維手勢之介面系統」，碩士論文，國立清華大學資訊工程所，新竹，民國93年。

[23] 張國君，「基於電腦視覺的手勢辨識系統」，碩士論文，國立清華大學電機工程學系，新竹，民國94年。

[24] 簡敬宇，「以視覺為基礎之使用多重攝影機之即時手臂指向追蹤及辨識系統」，碩士論文，國立清華大學電機工程學系，新竹，民國95年。

書籍

[25] 郭正邦，台灣的微電子世界，麥格羅 希爾，台北，1997。

網路資源
[26] DLT method: http://kwon3d.com/theory/dlt/dlt.html
Update by Young-Hoo Kwon (2003/03/03)

[27] Eye Toy: http://www.eyetoy.com/
Sony Computer Entertainment Cooperation, Europe. (2003)