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ee.Kernel.compass
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Generates a 3x3 Prewitt's Compass edge-detection kernel.
| Usage | Returns | ee.Kernel.compass(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 Prewitt compass kernel', ee.Kernel.compass());
/**
* Output weights matrix
*
* [1, 1, -1]
* [1, -2, -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 Prewitt compass kernel:')
pprint(ee.Kernel.compass().getInfo())
# Output weights matrix
# [1, 1, -1]
# [1, -2, -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 Prewitt's Compass kernel for edge detection in images.\u003c/p\u003e\n"],["\u003cp\u003eAllows for customization by scaling the kernel values with a magnitude argument.\u003c/p\u003e\n"],["\u003cp\u003eOffers an option to normalize the kernel values, ensuring they sum to 1.\u003c/p\u003e\n"],["\u003cp\u003eProvides usage examples in JavaScript, Python, and Colab environments.\u003c/p\u003e\n"]]],["The core function is `ee.Kernel.compass()`, which creates a 3x3 Prewitt compass edge-detection kernel. The function accepts two arguments: `magnitude` (a float to scale values, defaulting to 1) and `normalize` (a boolean to normalize the kernel values to sum to 1, defaulting to false). The output is a kernel with weights represented as `[[1, 1, -1], [1, -2, -1], [1, 1, -1]]`.\n"],null,["# ee.Kernel.compass\n\nGenerates a 3x3 Prewitt's Compass edge-detection kernel.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|----------------------------------------------------|---------|\n| `ee.Kernel.compass(`*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 Prewitt compass kernel', ee.Kernel.compass());\n\n/**\n * Output weights matrix\n *\n * [1, 1, -1]\n * [1, -2, -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 Prewitt compass kernel:')\npprint(ee.Kernel.compass().getInfo())\n\n# Output weights matrix\n\n# [1, 1, -1]\n# [1, -2, -1]\n# [1, 1, -1]\n```"]]