Updates the motion history image as following:
mhi(x,y)=timestamp if silhouette(x,y)!=0
0 if silhouette(x,y)=0 and mhi(x,y)<timestamp-duration
mhi(x,y) otherwise
That is, MHI pixels where motion occurs are set to the current timestamp, while the pixels where motion happened far ago are cleared.


- silhouette (IntPtr)
- Silhouette mask that has non-zero pixels where the motion occurs.
- mhi (IntPtr)
- Motion history image, that is updated by the function (single-channel, 32-bit floating-point)
- timestamp (Double)
- Current time in milliseconds or other units.
- duration (Double)
- Maximal duration of motion track in the same units as timestamp.