未來工作

1. 以更高階的特徵判斷人臉區域：本系統現階段所採取的兩個特徵，邊緣反應 和 gradient 方向之變異數表現尚不夠穩定，在不同教室和影片中所產生的數 值不盡相同。

2. 以橢圓逼近人臉：目前只做人臉膚色區域的選取，為本系統無法抵抗膚色區 域重疊的主要原因。某些膚色區域不只包含人臉，可能也同時包含了後方學 生的手部等膚色區域，如果能夠以橢圓逼近人臉，將人臉由重疊的膚色區塊 中分離開來，便能夠有效率的提升偵測的正確率。

3. 膚色增強以及照明情況分析：對於某些特別陰暗的教室環境，為了能夠讓膚 色完整，可以事先做膚色增強的動作。此外，系統也能夠對於背景影像事先 做一些照明情況的分析，以對演算法進行微調的動作。

4. 人臉追蹤：以適當的特徵進行人臉追蹤，以增強人臉偵測的穩定性。

本研究在去背景與膚色偵測兩個部分提供了穩定且優良的基礎。未來期望能 夠以此基礎，改良人臉偵測的分法，以期進一步偵測人臉的頭部姿勢與凝視角 度，以夠分析學生們的行為，達到自動進行教室觀察的目的。

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參考文獻

L. Cheng, M. Gong, D. Schuurmans, and T. Caelli, "Real-Time Discriminative Background Subtraction," IEEE Transactions on Image Processing, vol. 20, no. 5, pp.

1401-1414, 2010.

Z. Wu and R. Leahy, "An Optimal Graph Theoretic Approach to Data Clustering:

Theory and its Application to Image Segmentation," IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 15, no. 11, pp. 1101-1113, 1993.

O. Juan and Y. Boykov, "Interactive Graph Cuts," IEEE Computer Society Conference on Computer Vision and Pattern Recognition, New York, pp. 1023-1029, 2006.

P. Kohli, "Dynamic Graph Cuts for Efficient Inference in Markov Random Fields,"

IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 29, no. 12, pp.

2079-2088, 2007.

Y. Boykov, "An Experimental Comparison of Min-cut/Max-flow Algorithms for Energy Minimization in Vision," IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 26, no. 9, pp. 1124-1137, 2004.

P. Kae and R. Bow, "An Improved Adaptive Background Mixture Model for Real-Time Tracking with Shadow Detection," Proceedings of the 2nd European Workshop on Advanced Video-Based Surveillance Systems, London, 2001.

O. Carmichael and M. Hebert, "Shape-Based Recognition of Wiry Objects," IEEE Transactions on Pattern Analysis and Machine Intelligence, pp.1537-1552, vol.26, no.12, Dec. 2004.

92

C. Stauffer and W. E. L. Grimson, "Learning Patterns of Activity using Real-Time Tracking," IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 22, no. 8, pp. 747-757, 2000.

A. M. Elgammal, R. Duraiswami, D. Harwood, and L. S. Davis, "Background and Foreground Modeling using Nonparametric Kernel Density Estimation for Visual Surveillance," Proceedings of the IEEE, vol. 90, no. 7, pp. 1151-1163, 2002.

A. M. Elgammal, D. Harwood, and L. S. Davis, "Non-Parametric Model for Background Subtraction," Proceedings of the 6th European Conference on Computer Vision-Part II (ECCV '00), pp. 751-767, London, 2000.

K. Kim, T. H. Chalidabhongse, D. Harwood, and L. Davis, "Real-Time Foreground-Background Segmentation using Codebook Model," RealTime Imaging, vol. 11, no. 3, pp. 172-185, 2005.

R. Lienhart, L. Liang, and A. Kuranov, "A Detector Tree of Boosted Classifier for Real-Time Object Detection and Tracking," Proceedings of International Conference on Multimedia and Expo (ICME '03), vol.2, pp. II-277-280, Baltimore, Maryland, 2003.

L. M. Huang, C. S. Ouyang, and S. J. Lee, "A Neuro-Fuzzy Approach for Multiple Human Objects Segmentation," Proceedings of the IEEE International Conference on Systems, Man and Cybernetics, vol. 3, pp. 2815-2820, Washington, 2003.

Y. Yacoob and L. S. Davis, "Detection and Analysis of Hair," IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 28, no. 7, pp. 1164-1169, 2006.

K. C. Lee, D. Anguelov, B. Sumengen, and S. B. Gokturk, "Unsupervised Learning from Local Features for Video-Based Face Recognition," Proceedings of the 8th IEEE International Conference on Automatic Face & Gesture Recognition (FG '08), pp.

1-6, Amsterdam, The Netherlands, 2008.

93

P. Viola and M. J. Jones, "Robust Real-Time Face Detection," International Journal of Computer Vision, vol. 2, no. 57, pp. 137-154, 2004.

A. H. Gee and R. Cipolla, "Determining the Gaze of Faces in Images," Image and Vision Computing, vol. 12, pp. 639-647, 1994.

J. G. Wang and E. Sung, "EM Enhancement of 3D Head Pose Estimated by Point at Infinity," Image and Vision Computing, vol. 25, no. 12, pp. 1864-1874, 2007.

P. Campadelli and R. Lanzarotti, "A Face Recognition System Based on Local Feature Analysis," Proceedings of the 4th international conference on Audio- and video-based biometric person authentication(AVBPA'03), pp. 68-73, Springer-Verlag Berlin, Heidelberg, 2003.

E. Hjelmås and B. K. Low, "Face Detection: A Survey," Computer Vision and Image Understanding, vol. 83, no. 3, pp. 236-274, 2001.

J. Tu, Y. Fu, and T. S. Huang, "Locating Nose-Tips and Estimating Head Poses in Images by Tensorposes," IEEE Transactions on Circuits and Systems for Video Technology, vol. 19 , no. 1, pp. 90-102, 2009.

P. Martins and J. Batista, "Single View Head Pose Estimation," Proceedings of the 15th IEEE International Conference on Image Processing (ICIP '08), pp. 1652-1655, San Diego, California, USA, 2008.

Q. Li, Y. Mao, Z. Wang, and W. Xiang, "Robust Real-Time Detection of Abandoned and Removed Objects," Proceedings of the 5th International Conference on Image and Graphics (ICIG '09), pp. 156-161, Xi'an, China, 2009.

S. C. Huang, "An Advanced Motion Detection Algorithm with Video Quality Analysis for Video Surveillance Systems," IEEE Transactions on Circuits and Systems for Video Technology, vol. 21, no. 1, pp. 1-14, 2011.

94

M. Vargas, J. M. Milla, S. L. Toral, and F. Barrero, "An Enhanced Background Estimation Algorithm for Vehicle Detection in Urban Traffic Scenes," IEEE Transactions on Vehicular Technology, vol. 59, no. 8, pp. 3694-3709, 2010.

W. Wang, J. Yang, and W. Gao, "Modeling Background and Segmenting Moving Objects from Compressed Video," IEEE Transactions on Circuits and Systems for Video Technology, vol. 18, no. 5, pp. 670-681, 2008.

K. Huang, S. Wang, T. Tan, and S. J. Maybank, "Human Behavior Analysis Based on a New Motion Descriptor," IEEE Transactions on Circuits and Systems for Video Technology, vol. 19, no. 12, pp. 1830-1840, 2009.

H. Wang, Q. Lu, X. Wang, G. Lv, and L. Xu, "Method for video incident detection based on biological visual Mechanism," Proceedings of IEEE International Conference on Automation and Logistics (ICAL '10), pp. 114-119, Hong Kong, 2010.

L. Wang, L. Wang, M. Wen, Q. Zhuo, and W. Wang, "Background Subtraction using Incremental Subspace Learning," Proceedings of IEEE International Conference on Image Processing(ICIP '07), vol. 5, pp. 45-48, San Antonio, Texas, USA, 2007.

Y. Liu and Y. Li, "Robust Moving Object Region Extraction Using a Column and Row Projection Algorithm," Proceedings of the 3rd International Conference on Advanced Computer Theory and Engineering (ICACTE '10), vol. 6, pp. 168-171, Chengdu, China, 2010.

C. C. Chiu, M. Y. Ku, and L. W. Liang, "A Robust Object Segmentation System Using a Probability-Based Background Extraction Algorithm," IEEE Transactions on Circuits and Systems for Video Technology, vol. 20, no. 4, pp. 518-528, 2010.

Y. Mu, H. Zhang, H. Wang, and W. Zuo, "Automatic Video Object Segmentation using Graph Cut," Proceedings of IEEE International Conference on Image Processing(ICIP '07), vol. 3, pp. III-377-III-380, San Antonio, Texas, USA, 2007.

95

J. Park, A. Tabb, and A. C. Kak, "Hierarchical Data Structure for Real-Time Background Subtraction," Proceedings of IEEE International Conference on Image Processing(ICIP '06), pp. 1849-1852, 8-11, Atlanta, GA, USA, 2006.

X. N. Zhang, J. Jiang, Z. H. Liang and C. L. Liu, "Skin Color Enhancement Based on Favorite Skin Color in HSV Color Space," IEEE Transactions on Consumer Electronics, vol. 56, no. 3, pp.1789-1793, 2010.

D. Chai and K. N. Ngan, "Face Segmentation Using Skin-Color Map in Videophone Applications," IEEE Transactions on Circuits and Systems for Video Technology, vol.

9, no. 4, pp. 551-564, 1999.

Z. Liu, J. Yang and N. S. Peng, "An Efficient Face Segmentation Algorithm Based on Binary Partition Tree," Proceedings of Signal Processing:Image Communication, vol.

20, no. 4, pp. 295-314, Shanghai, 2005.

H. Sahbi and N. Boujemaa, "Coarse to Fine Face Detection Based on Skin ColorAdaption," Proceedings of the International ECCV Workshop, pp. 112-120, Copenhagen, 2002.

T. M. Mahmoud, "A New Fast Skin Color Detection Technique," World Academy of Science, Engineering and Technology, pp. 501-505, 2008.

S. K. Singh, D. S. Chauhan, M. Vatsa and R. Singh, "A Robust Skin Color Based Face Detection Algorithm," Tamkang Journal of Science and Engineering, vol. 6, no. 4, pp.

227-234, 2003.

S. A. Phung, "A Novel Skin Color Model in YCbCr Color Space And Its Application to Human Face Detection," Proceedings of IEEE International Conference on Image Processing(ICIP '02), vol. 1, I-289 - I-292, New York, 2002.

L. Sigal, S. Sclaroff and V. Athitsos, " Skin Color-based Video Segmentation Under Time-varying Illumination," IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 26, no. 7, pp. 862-877, 2004.

96

M. Ying, "Automatic Video Object Segmentation Using Graph Cut," Proceedings of IEEE International Conference on Image Processing(ICIP '07), vol. 3, pp. III-377 - III-380, Texas, Usa, 2007.

C. Rother, V. Kolmogorov, and A. Blake, "Grabcut—Interactive Foreground Extraction Using Iterated Graph Cuts," ACM Transactions on Graphics (SIGGRAPH), pp.309-314, New York, 2004.