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)

from pprint import pprint

print('A Laplacian-4 kernel:')
pprint(ee.Kernel.laplacian4().getInfo())

#  Output weights matrix

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