ee.Kernel.add

AI-generated Key Takeaways

• The Kernel.add method performs pointwise addition of two kernels after aligning their centers.

• This method returns a new Kernel object representing the sum.

• The normalize argument, which defaults to false, determines whether the resulting kernel is normalized.

• The examples show how two kernels with different dimensions are added and the resulting kernel weights.

Adds two kernels (pointwise) after aligning their centers.

Usage	Returns
Kernel.add(kernel2, normalize)	Kernel

Argument	Type	Details
this: kernel1	Kernel	The first kernel.
kernel2	Kernel	The second kernel.
normalize	Boolean, default: false	Normalize the kernel.

Examples

Code Editor (JavaScript)

// Two kernels, they do not need to have the same dimensions.
var kernelA = ee.Kernel.chebyshev({radius: 3});
var kernelB = ee.Kernel.square({radius: 1, normalize: false, magnitude: 100});
print(kernelA, kernelB);

/**
 * Two kernel weights matrices
 *
 *   [3, 3, 3, 3, 3, 3, 3]
 *   [3, 2, 2, 2, 2, 2, 3]
 *   [3, 2, 1, 1, 1, 2, 3]       [100, 100, 100]
 * A [3, 2, 1, 0, 1, 2, 3]     B [100, 100, 100]
 *   [3, 2, 1, 1, 1, 2, 3]       [100, 100, 100]
 *   [3, 2, 2, 2, 2, 2, 3]
 *   [3, 3, 3, 3, 3, 3, 3]
 */

print('Pointwise addition of two kernels', kernelA.add(kernelB));

/**
 * [3, 3,   3,   3,   3, 3, 3]
 * [3, 2,   2,   2,   2, 2, 3]
 * [3, 2, 101, 101, 101, 2, 3]
 * [3, 2, 101, 100, 101, 2, 3]
 * [3, 2, 101, 101, 101, 2, 3]
 * [3, 2,   2,   2,   2, 2, 3]
 * [3, 3,   3,   3,   3, 3, 3]
 */

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

# Two kernels, they do not need to have the same dimensions.
kernel_a = ee.Kernel.chebyshev(**{'radius': ee.Number(3)})
kernel_b = ee.Kernel.square(**{
    'radius': 1,
    'normalize': False,
    'magnitude': 100
})
pprint(kernel_a.getInfo())
pprint(kernel_b.getInfo())

#  Two kernel weights matrices

#   [3, 3, 3, 3, 3, 3, 3]
#   [3, 2, 2, 2, 2, 2, 3]
#   [3, 2, 1, 1, 1, 2, 3]       [100, 100, 100]
# A [3, 2, 1, 0, 1, 2, 3]     B [100, 100, 100]
#   [3, 2, 1, 1, 1, 2, 3]       [100, 100, 100]
#   [3, 2, 2, 2, 2, 2, 3]
#   [3, 3, 3, 3, 3, 3, 3]

print('Pointwise addition of two kernels:')
pprint(kernel_a.add(kernel_b).getInfo())

#  [3, 3,   3,   3,   3, 3, 3]
#  [3, 2,   2,   2,   2, 2, 3]
#  [3, 2, 101, 101, 101, 2, 3]
#  [3, 2, 101, 100, 101, 2, 3]
#  [3, 2, 101, 101, 101, 2, 3]
#  [3, 2,   2,   2,   2, 2, 3]
#  [3, 3,   3,   3,   3, 3, 3]