MPEG-7 Motion Descriptors. Reference. ISO/IEC JTC1/SC29/WG11 N4031 ISO/IEC JTC1/SC29/WG11 N4062 MPEG-7 Visual Motion Descriptors (IEEE Transactions on Circuits and Systems for Video Technology) Video Indexing using Descriptors of Spatial Distribution of Motion Activity
MPEG-7 Motion Descriptors
(IEEE Transactions on Circuits and Systems for Video Technology)
(submitted to IEEE Transactions on Circuits and Systems for Video Technology)
1 – very low activity2 – low activity3 – medium activity4 – high activity5 – very high activity
if(std_dev<t1)intensity = 1;else if(std_dev<t2)intensity = 2;else if(std_dev<t3)intensity = 3;else if(std_dev<t4)intensity = 4;elseintensity = 5;
t1 = 0.257*l/F
t2 = 0.706*l/F
t3 = 1.280*l/F
t4 = 2.111*l/F
diagonal length l = sqrt(w*w + h*h)
F is the frame rate in frames/second.
The dark area consists of macroblocks that get non-zero values after thresholding.
The remaining area consists of macroblocks that get “zero out” after thresholding.
With smaller,widely spaced objects note that there are more long-run lengths and medium run-lengths
The motion-activity intensity descriptor enables selection of the video segments of a program based on intensity of motion activity.
We can use motion activity to separate the high and low motion parts of the video sequence and or as a first stage content filter.