Emgu CV Library Documentation
cvUpdateMotionHistory Method (silhouette, mhi, timestamp, duration)
NamespacesEmgu.CVCvInvokecvUpdateMotionHistory(IntPtr, IntPtr, Double, Double)

www.emgu.com/wiki
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.
Declaration Syntax
C#Visual BasicVisual C++
public static void cvUpdateMotionHistory(
	IntPtr silhouette,
	IntPtr mhi,
	double timestamp,
	double duration
)
Public Shared Sub cvUpdateMotionHistory ( _
	silhouette As IntPtr, _
	mhi As IntPtr, _
	timestamp As Double, _
	duration As Double _
)
public:
static void cvUpdateMotionHistory(
	IntPtr silhouette, 
	IntPtr mhi, 
	double timestamp, 
	double duration
)
Parameters
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.

Assembly: Emgu.CV (Module: Emgu.CV) Version: 1.3.0.0 (1.3.0.0)