Spatial Gaussian Gradient Magnitude filter

Spatial Gaussian Gradient Magnitude filter.

The Spatial Gaussian Gradient Magnitude filter computes the magnitude of the gradient of an image using Gaussian derivatives, providing a measure of the strength of the gradient at each pixel and helping to highlight edges and transitions in the image. The filter operates by convolving the image with a pair of Gaussian derivative kernels—one for the x-direction and another for the y-direction. These kernels are derived from the Gaussian function and are used to estimate the image gradient in both the horizontal and vertical directions.

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 gaussian_gradient_magnitude for information on different parameters. Default:

from scipy.ndimage.filters import gaussian_gradient_magnitude

function = lambda array: gaussian_gradient_magnitude\(array, sigma=1\)

Outputs

Output raster layer [rasterDestination]: Raster file destination.

Command-line usage

>qgis_process help enmapbox:SpatialGaussianGradientMagnitudeFilter:

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

function = lambda array: gaussian_gradient_magnitude(array, sigma=1)
    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
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outputRaster: <outputRaster>
    Output raster layer