Emgu CV Library Documentation
cvLog Method (src, dst)
NamespacesEmgu.CVCvInvokecvLog(IntPtr, IntPtr)

www.emgu.com/wiki
Calculates natural logarithm of absolute value of every element of input array: dst(I)=log(abs(src(I))), src(I)!=0 dst(I)=C, src(I)=0 Where C is large negative number (-700 in the current implementation)
Declaration Syntax
C#Visual BasicVisual C++
public static void cvLog(
	IntPtr src,
	IntPtr dst
)
Public Shared Sub cvLog ( _
	src As IntPtr, _
	dst As IntPtr _
)
public:
static void cvLog(
	IntPtr src, 
	IntPtr dst
)
Parameters
src (IntPtr)
The source array
dst (IntPtr)
The destination array, it should have double type or the same type as the source

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