Spatial morphological White Top-Hat filter

Spatial morphological White Top-Hat filter. See Wikipedia for general information.

The Spatial morphological White Top-Hat filter is used to extract and enhance small bright structures or features from an image. It is achieved through a combination of morphological closing and subtraction operations, isolating the desired components while suppressing lower intensity regions.

Usage:

Start the algorithm from the Processing Toolbox panel.
Select the raster to process and modify the parameterization if necessary, then click run.
Processed image in comparison to the original.

Parameters

Raster layer [raster]

Raster layer to be processed band-wise.

Function [string]

Python code. See scipy.ndimage.white_tophat for information on different parameters. Default:

from scipy.ndimage import white_tophat

function = lambda array: white_tophat\(array, size=\(3, 3\)\)

Outputs

Output raster layer [rasterDestination]: Raster file destination.

Command-line usage

>qgis_process help enmapbox:SpatialMorphologicalWhiteTophatFilter:

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Arguments
----------------

raster: Raster layer
    Argument type:  raster
    Acceptable values:
            - Path to a raster layer
function: Function
    Default value:  from scipy.ndimage import white_tophat

function = lambda array: white_tophat(array, size=(3, 3))
    Argument type:  string
    Acceptable values:
            - String value
            - field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field
            - expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression
outputRaster: Output raster layer
    Argument type:  rasterDestination
    Acceptable values:
            - Path for new raster layer

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Outputs
----------------

outputRaster: <outputRaster>
    Output raster layer