VISUAL RECOGNITION OF EVENTS AND ACTIVITIES BASED ON MOMENTUM OF MOTION ENERGY MASS

Figures & data

FIGURE 1 General block diagram of the recognition process. (Figure is provided in color online.)

FIGURE 2 Calculation of velocity of motion energy mass in (a) horizontal and (b) vertical directions. (Figure is provided in color online.)

FIGURE 3 Representation of the application of the angular transform on the MoT of the running activity.

FIGURE 4 Template construction using activities from the KTH database. (a) Representative frames, (b) horizontal MoT templates, (c) vertical MoT templates, (d) angular representation of MoT templates in a combined feature vector. (Figure is provided in color online.)

FIGURE 5 Calculation of displacements in case of diagonal motion. The observed deviations from a straight path are due to actual vertical motion while the acting person is walking along the motion path.

FIGURE 6 Six types of activities in the KTH database: (a) boxing, (b) claping, (c) waving, (d) walking, (e) jogging, (f) running.

TABLE 1 Comparison with Activity History Areas for a Subset of Activities of the KTH Database

Methods	Boxing	Handclapping	Handwaving
AMoT	97.22	88.89	98.15
Activity History Areas	75.49	79.45	87.15

TABLE 2 Performance Comparison Between the Momentum Template and the Angular Transformed Momentum Template with LDA

Action	MoT	AMoT
Boxing	88.89	97.22
Handclapping	87.04	88.89
Handwaving	94.44	98.15
Walking	87.96	89.81
Jogging	75.93	81.48
Running	84.26	86.11

TABLE 3 Performance of Our Method With and Without Compensation for Diagonal Motion

Methods	Walking	Jogging	Running
With	86.11	77.78	83.33
Without	72.23	58.33	77.78

TABLE 4 Comparison Between Different Approaches

Methods	Recognition rate
AMoT (this work)	90.28
MMD (Danafar, Giusti, and Schmidhuber 2010)	94.43
SVM-BTA (Qian, Mao, Xiang, and Wang 2010)	88.69
pLSA + spatial-temporal words (Niebles, Wang, and Li 2008)	83.33
SVM + MGD & Hist. of MHI (Meng and Pears 2009)	80.3
SVM on local feature (Schuldt, Laptev, and Caputo 2004)	71.7

TABLE 5 Confusion Matrix

Action	Boxing	Handclapping	Handwaving	Walking	Jogging	Running
Boxing	97.22	1.85	0.93	0	0	0
Handclapping	8.33	88.89	2.78	0	0	0
Handwaving	0.93	0.93	98.15	0	0	0
Walking	0	0	0	89.81	9.26	0.93
Jogging	0	0	0	10.19	81.48	8.33
Running	0	0	0	0.93	12.96	86.11

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