LaplacianKernel Task

This task returns a Laplacian kernel for use with convolution filtering. A Laplacian kernel consists of a high central value surrounded by negative weights in the north-south and east-west directions, with zero values at the kernel corners.

Example

; Start the application

e = ENVI(/HEADLESS)

; Open an input file

File = Filepath('qb_boulder_msi', Subdir=['data'], $

  Root_Dir=e.Root_Dir)

Raster = e.OpenRaster(File)

; Get the task from the catalog of ENVITasks

Task = ENVITask('LaplacianKernel')

; Define inputs

Task.KERNEL_SIZE = [3,5]

; Run the task

Task.Execute

; Print the resulting kernel

Print, Task.OUTPUT_KERNEL

IDL prints:

0.000000     -1.00000     0.000000

-1.00000     -2.00000     -1.00000

-2.00000      14.0000     -2.00000

-1.00000     -2.00000     -1.00000

0.000000     -1.00000     0.000000

Syntax

Result = ENVITask('LaplacianKernel')

Input properties (Set, Get): KERNEL_SIZE

Output properties (Get only): OUTPUT_KERNEL

Properties marked as "Set" are those that you can set to specific values. You can also retrieve their current values any time. Properties marked as "Get" are those whose values you can retrieve but not set.