ArcGIS Developer Help

IRasterConvolutionFilter Interface

Provides access to members that control a raster kernel-based filter.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Description

IRasterConvolutionFilter provides access to members that allow setting up a convolution filter. PutCoefficients() and QueryCoefficients() sets and gets kernel coefficients, which are represented as a double array.
QueryCoefficients() expects the array to be allocated by caller, and it fills in the values.

Members

	Name	Description
	GainFactor	The gain factor of the kernel filter.
	GetCenterPosition	Gets the center position of the kernel filter.
	GetSize	Gets the size of the kernel filter.
	IsNormalized	Indicates whether the filter is normalized.
	Normalize	Normalizes the filter.
	PutCoefficients	Sets the element coefficients of the kernel filter.
	QueryCoefficients	Gets the element coefficients of the kernel filter.
	Recursive	Indicates whether the filter is recursive.
	ScaleBy	Scales the filter coefficients.
	SetCenterPosition	Sets the center position of the kernel filter.
	SetSize	Sets the size of the kernel filter.

Classes that implement IRasterConvolutionFilter

Classes	Description
RasterConvolutionFilter	A raster kernel-based filter.

Remarks

The IRasterConvlutionFilter interface is used to create a convolution filter, which can be used to apply on a raster to perform image filtering. To create a convolution filter, the size, values and the center of the kernel must be set.

Here is an example of low pass filter kernel

A 3x3 low pass filter kernel

Use SetSize, SetCenterPosition, and PutCoefficents to define a kernel.