Motion Direction Inconsistency-Based Fight Detection for Multiview Surveillance Videos

Algorithm 1

Feature Extraction algorithm.

Inputs: the video

Outputs: the final feature vectors

 1: for each frame of do

 2:  Compute optical flow vectors () by Equation (2)

 3:  Converted () to the polar coordinate form by Equations (3) and (4)

 4:  Compute , , , by Equations (5), (6), (7), and (8)

 5:  ifthen

 6:   

 7:  else

 8:   

 9:  ifthen

 10:   

 11:  else

 12:   

 13:  Compute MoDI by Equation (9)

 14:  Compute WMoDI by Equation (10)

 15:  Compute descriptors , , and by Equations (11), (12), and (13)

 16:  Obtain smoothed descriptors by (15)

 17: end for

 18: Calculate the statistical characteristics of smoothed descriptors

 19: Concatenate the statistical characteristics to generate the final vectors