Tool Name	Shrink and Expand
Tool ID	28
Library ID	grid_tools
Version	1.0
Author(s)	V.Wichmann & O.Conrad (c) 2011

Description

With this tool you can shrink and/or expand regions with valid data by a certain distance defined by the (kernel) radius. Shrinking just invalidates all (valid) data cells found within the given distance to no-data cells, while expansion replaces no-data cells with new values based on the evaluation of all (valid) data cells found within the neighbourhood as defined by the kernel. Both operations can be combined.

The method for the value expansion can be chosen as minimum, maximum, mean or majority value. The neighbourhood can be evaluated either at once or in a stepwise iterative way.

Parameters

Name	Type	Identifier	Description	Constraints
Input
Grid	grid, input	INPUT
Output
Result	grid, output, optional	RESULT
Options
Operation	choice	OPERATION		Available Choices: [0] shrink [1] expand [2] shrink and expand [3] expand and shrink Default: 3
Search Mode	choice	CIRCLE	Choose the shape of the kernel.	Available Choices: [0] Square [1] Circle Default: 1
Radius	integer number	RADIUS	The kernel radius [cells].	Minimum: 1 Default: 1
Method	choice	EXPAND	Choose how to fill no-data cells.	Available Choices: [0] minimum [1] maximum [2] mean [3] majority Default: 3
Preserve Data Type	boolean	KEEP_TYPE	If false, mean value expansion results will be stored with floating point precision.	Default: 1
Iterative Expansion	boolean	ITERATIVE	If false, the neighbourhood for expansion is evaluated in one step, else expansion is done stepwise with a one cell radius for each iteration until desired kernel radius is reached.	Default: 0