Filters

User-defined average filters

The standard average filter is AVG3x3; it calculates the average value of 9 pixel values considered. In the Filter dialog box as well as on the command line, you may define other average filters of any user-defined size.

Using the Filter dialog box:

To use the standard Average filter AVG3x3:

Open the Filter dialog box,
for Filter Type, select: Linear,
for Filter Name, select: Avg3x3.

To define your own average filter:

Open the Filter dialog box,
for Filter Type, select: Average,
specify the size of the filter.

See also the example below.

Using the command line (advanced):

To use the standard Average filter AVG3x3, type on the command line of the Main window:

OUTMAP

MapFilter(InputMapName,Avg3x3)

where:

	OUTMAP	is the name of your output map.
	MapFilter	is the command to start the Filter operation.
	InputMapName	is the name of your input map.
	Avg3x3	is the name of the standard average filter.

To define your own Average filter, type the following expression on the command line of the Main window:

OUTMAP

MapFilter(InputMapName,Average(rows , cols))

where:

	OUTMAP	is the name of your output map.
	MapFilter	is the command to start the Filter operation.
	InputMapName	is the name of your input map.
	Average	is the command to define an average filter.
	rows	are the number of rows of your average filter.
	cols	are the number of columns of your average filter.

Example:

To use an average filter which considers each 5 vertically neighbouring pixels:

in the Filter : dialog box, choose for Filter type: Average,

specify 5 for the number of rows and 1 for the number of columns,

on the command line, use a filter definition of: Average(5,1).

Tip:

Both the number of rows and the number of columns defining the filter size must be odd values.