Announcement: All noncommercial projects registered to use Earth Engine before
April 15, 2025 must
verify noncommercial eligibility to maintain Earth Engine access.
ee.Kernel.laplacian8
Stay organized with collections
Save and categorize content based on your preferences.
Generates a 3x3 Laplacian-8 edge-detection kernel.
| Usage | Returns | ee.Kernel.laplacian8(magnitude, normalize) | Kernel |
| Argument | Type | Details | magnitude | Float, default: 1 | Scale each value by this amount. |
normalize | Boolean, default: false | Normalize the kernel values to sum to 1. |
Examples
Code Editor (JavaScript)
print('A Laplacian-8 kernel', ee.Kernel.laplacian8());
/**
* Output weights matrix
*
* [1, 1, 1]
* [1, -8, 1]
* [1, 1, 1]
*/
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-8 kernel:')
pprint(ee.Kernel.laplacian8().getInfo())
# Output weights matrix
# [1, 1, 1]
# [1, -8, 1]
# [1, 1, 1]
Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License. For details, see the Google Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates.
Last updated 2023-10-06 UTC.
[null,null,["Last updated 2023-10-06 UTC."],[[["\u003cp\u003eCreates a 3x3 kernel for edge detection using the Laplacian-8 algorithm.\u003c/p\u003e\n"],["\u003cp\u003eThe kernel has a center weight of -8 and surrounding weights of 1, enhancing edges in an image.\u003c/p\u003e\n"],["\u003cp\u003eUsers can adjust the \u003ccode\u003emagnitude\u003c/code\u003e to scale the kernel values and \u003ccode\u003enormalize\u003c/code\u003e them to sum to 1.\u003c/p\u003e\n"]]],["The `ee.Kernel.laplacian8()` function generates a 3x3 Laplacian-8 edge-detection kernel. It accepts two optional arguments: `magnitude` (float, default 1) to scale kernel values, and `normalize` (boolean, default false) to normalize values to sum to 1. The function returns a Kernel object. The default kernel matrix consists of ones around the perimeter and negative eight in the center: [[1, 1, 1], [1, -8, 1], [1, 1, 1]].\n"],null,["# ee.Kernel.laplacian8\n\nGenerates a 3x3 Laplacian-8 edge-detection kernel.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|-------------------------------------------------------|---------|\n| `ee.Kernel.laplacian8(`*magnitude* `, `*normalize*`)` | Kernel |\n\n| Argument | Type | Details |\n|-------------|-------------------------|------------------------------------------|\n| `magnitude` | Float, default: 1 | Scale each value by this amount. |\n| `normalize` | Boolean, default: false | Normalize the kernel values to sum to 1. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\nprint('A Laplacian-8 kernel', ee.Kernel.laplacian8());\n\n/**\n * Output weights matrix\n *\n * [1, 1, 1]\n * [1, -8, 1]\n * [1, 1, 1]\n */\n```\nPython setup\n\nSee the [Python Environment](/earth-engine/guides/python_install) page for information on the Python API and using\n`geemap` for interactive development. \n\n```python\nimport ee\nimport geemap.core as geemap\n```\n\n### Colab (Python)\n\n```python\nfrom pprint import pprint\n\nprint('A Laplacian-8 kernel:')\npprint(ee.Kernel.laplacian8().getInfo())\n\n# Output weights matrix\n\n# [1, 1, 1]\n# [1, -8, 1]\n# [1, 1, 1]\n```"]]