ee.Kernel.laplacian4

  • The ee.Kernel.laplacian4() function generates a 3x3 Laplacian-4 edge-detection kernel.

  • The magnitude argument can be used to scale the kernel values, and the normalize argument can be used to normalize the kernel values to sum to 1.

  • Examples are provided for using the ee.Kernel.laplacian4() function in both the Earth Engine Code Editor (JavaScript) and a Colab notebook (Python).

 Generates a 3x3 Laplacian-4 edge-detection kernel.

UsageReturns
ee.Kernel.laplacian4(magnitude, normalize)Kernel
ArgumentTypeDetails
magnitudeFloat, default: 1Scale each value by this amount.
normalizeBoolean, default: falseNormalize the kernel values to sum to 1.

Examples

Code Editor (JavaScript)

print('A Laplacian-4 kernel', ee.Kernel.laplacian4());

/**
 * Output weights matrix
 *
 * [0,  1, 0]
 * [1, -4, 1]
 * [0,  1, 0]
 */

Python setup

See the Python Environment page for information on the Python API and using geemap for interactive development.

import ee
import geemap.core as geemap

Colab (Python)

display('A Laplacian-4 kernel:', ee.Kernel.laplacian4())

#  Output weights matrix

#  [0,  1, 0]
#  [1, -4, 1]
#  [0,  1, 0]