This task returns a low pass kernel of a specified size, for use with convolution filtering. ENVI’s low pass filter contains the same weights in each kernel element. The default kernel size is 3x3.

Example

---

; Start the application

e = ENVI(/HEADLESS)

; Get the task from the catalog of ENVITasks

Task = ENVITask('LowPassKernel')

; Define outputs

Task.KERNEL_SIZE = [3,5]

; Run the task

Task.Execute

; Print the resulting 3x5 kernel

print, Task.OUTPUT_KERNEL

IDL prints:

0.0666667    0.0666667    0.0666667

0.0666667    0.0666667    0.0666667

0.0666667    0.0666667    0.0666667

 0.0666667    0.0666667    0.0666667

 0.0666667    0.0666667    0.0666667

Syntax

---

Result = ENVITask('LowPassKernel')

Input parameters (Set, Get): KERNEL_SIZE

Output parameters (Get only): OUTPUT_KERNEL

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

Input Parameters

---

KERNEL_SIZE (optional)

Specify a two-element array [n,m] as the kernel size, where n is the number of columns and m is the number of rows. The default kernel size is [3,3].

Output Parameters

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OUTPUT_KERNEL

This is the low pass kernel output.

Methods

---

Execute

Parameter

ParameterNames

Properties

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DESCRIPTION

DISPLAY_NAME

NAME

REVISION

TAGS

Version History

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ENVI 5.3

Introduced

See Also

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ENVITask, DirectionalFilter Task, DirectionalKernel Task, GaussianHighPassKernel Task, GaussianHighPassFilter Task, GaussianLowPassKernel Task, GaussianLowPassFilter Task, HighPassFilter Task, HighPassKernel Task, LaplacianFilter Task, LaplacianKernel Task, LowPassFilter Task, MedianFilter Task, RasterConvolution Task, SobelFilter Task, RobertsFilter Task