Emgu CV Library Documentation
cvPyrUp Method (src, dst, filter)
NamespacesEmgu.CVCvInvokecvPyrUp(IntPtr, IntPtr, FILTER_TYPE)

www.emgu.com/wiki
Performs up-sampling step of Gaussian pyramid decomposition. First it upsamples the source image by injecting even zero rows and columns and then convolves result with the specified filter multiplied by 4 for interpolation. So the destination image is four times larger than the source image.
Declaration Syntax
C#Visual BasicVisual C++
public static void cvPyrUp(
	IntPtr src,
	IntPtr dst,
	FILTER_TYPE filter
)
Public Shared Sub cvPyrUp ( _
	src As IntPtr, _
	dst As IntPtr, _
	filter As FILTER_TYPE _
)
public:
static void cvPyrUp(
	IntPtr src, 
	IntPtr dst, 
	FILTER_TYPE filter
)
Parameters
src (IntPtr)
The source image.
dst (IntPtr)
The destination image, should have 2x smaller width and height than the source.
filter (FILTER_TYPE)
Type of the filter used for convolution; only CV_GAUSSIAN_5x5 is currently supported.

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