This task returns a directional kernel for use with convolution filtering.
Example
e = ENVI(/HEADLESS)
Task = ENVITask('DirectionalKernel')
Task.KERNEL_SIZE = [3,5]
Task.ANGLE = 25.0
Task.Execute
print, Task.OUTPUT_KERNEL
IDL prints:
-1.32893 -0.422618 0.483689
-1.32893 -0.422618 0.483689
-0.906308 0.000000 0.906308
-0.483689 0.422618 1.32893
-0.483689 0.422618 1.32893
Syntax
Result = ENVITask('DirectionalKernel')
Input properties (Set, Get): ANGLE, 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.
Methods
This task inherits the following methods from ENVITask:
AddParameter
Execute
Parameter
ParameterNames
RemoveParameter
Properties
This task inherits the following properties from ENVITask:
COMMUTE_ON_DOWNSAMPLE
COMMUTE_ON_SUBSET
DESCRIPTION
DISPLAY_NAME
NAME
REVISION
TAGS
This task also contains the following properties:
ANGLE (required)
Specify the angle in degrees. The default value is 0.
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 value is [3,3].
OUTPUT_KERNEL
This is the directional kernel output.
Version History
API Version
4.3
See Also
ENVITask, DirectionalFilter Task, GaussianHighPassFilter Task, GaussianHighPassKernel Task, GaussianLowPassKernel Task, GaussianLowPassFilter Task, HighPassFilter Task, HighPassKernel Task, LaplacianFilter Task, LaplacianKernel Task, LowPassFilter Task, LowPassKernel Task, MedianFilter Task, RasterConvolution Task, SobelFilter Task, RobertsFilter Task