ee.Kernel.circle

  • Generates a circle-shaped kernel for use in image processing.

  • The kernel's radius can be specified in pixels or meters.

  • Kernel values can be normalized to sum to 1 and scaled by a magnitude factor.

  • Useful for operations like blurring or smoothing where a circular neighborhood is desired.

Generates a circle-shaped boolean kernel.

UsageReturns
ee.Kernel.circle(radius, units, normalize, magnitude)Kernel
ArgumentTypeDetails
radiusFloatThe radius of the kernel to generate.
unitsString, default: "pixels"The system of measurement for the kernel ('pixels' or 'meters'). If the kernel is specified in meters, it will resize when the zoom-level is changed.
normalizeBoolean, default: trueNormalize the kernel values to sum to 1.
magnitudeFloat, default: 1Scale each value by this amount.

Examples

Code Editor (JavaScript)

print('A circle kernel', ee.Kernel.circle({radius: 3}));

/**
 * Output weights matrix (up to 1/1000 precision for brevity)
 *
 * [0.000, 0.000, 0.000, 0.034, 0.000, 0.000, 0.000]
 * [0.000, 0.034, 0.034, 0.034, 0.034, 0.034, 0.000]
 * [0.000, 0.034, 0.034, 0.034, 0.034, 0.034, 0.000]
 * [0.034, 0.034, 0.034, 0.034, 0.034, 0.034, 0.034]
 * [0.000, 0.034, 0.034, 0.034, 0.034, 0.034, 0.000]
 * [0.000, 0.034, 0.034, 0.034, 0.034, 0.034, 0.000]
 * [0.000, 0.000, 0.000, 0.034, 0.000, 0.000, 0.000]
 */

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 circle kernel:')
pprint(ee.Kernel.circle(**{'radius': 3}).getInfo())

#  Output weights matrix (up to 1/1000 precision for brevity)

#  [0.000, 0.000, 0.000, 0.034, 0.000, 0.000, 0.000]
#  [0.000, 0.034, 0.034, 0.034, 0.034, 0.034, 0.000]
#  [0.000, 0.034, 0.034, 0.034, 0.034, 0.034, 0.000]
#  [0.034, 0.034, 0.034, 0.034, 0.034, 0.034, 0.034]
#  [0.000, 0.034, 0.034, 0.034, 0.034, 0.034, 0.000]
#  [0.000, 0.034, 0.034, 0.034, 0.034, 0.034, 0.000]
#  [0.000, 0.000, 0.000, 0.034, 0.000, 0.000, 0.000]