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ee.ImageCollection.first
使用集合让一切井井有条
根据您的偏好保存内容并对其进行分类。
返回指定集合中的第一个条目。
用法 | 返回 |
---|
ImageCollection.first() | 图片 |
参数 | 类型 | 详细信息 |
---|
此:imagecollection | ImageCollection | ImageCollection 实例。 |
示例
代码编辑器 (JavaScript)
var image = ee.ImageCollection('COPERNICUS/S2_SR').first();
Map.centerObject(image, 8);
var vis = {bands: ['B4', 'B3', 'B2'], min: 0, max: 5000};
Map.addLayer(image, vis, 'first of S2_SR');
// Display the image metadata.
print(image);
Python 设置
如需了解 Python API 和如何使用 geemap
进行交互式开发,请参阅
Python 环境页面。
import ee
import geemap.core as geemap
Colab (Python)
image = ee.ImageCollection('COPERNICUS/S2_SR').first()
m = geemap.Map()
m.center_object(image, 8)
vis = {'bands': ['B4', 'B3', 'B2'], 'min': 0, 'max': 5000}
m.add_layer(image, vis, 'first of S2_SR')
display(m)
# Display the image metadata.
display(image)
如未另行说明,那么本页面中的内容已根据知识共享署名 4.0 许可获得了许可,并且代码示例已根据 Apache 2.0 许可获得了许可。有关详情,请参阅 Google 开发者网站政策。Java 是 Oracle 和/或其关联公司的注册商标。
最后更新时间 (UTC):2025-07-26。
[null,null,["最后更新时间 (UTC):2025-07-26。"],[[["\u003cp\u003eThe \u003ccode\u003efirst()\u003c/code\u003e function retrieves the first image from an ImageCollection in Earth Engine.\u003c/p\u003e\n"],["\u003cp\u003eIt can be applied to any ImageCollection, like the 'COPERNICUS/S2_SR' dataset shown in the examples.\u003c/p\u003e\n"],["\u003cp\u003eUsers can then visualize and analyze this single image, displaying its metadata or adding it as a layer to a map.\u003c/p\u003e\n"],["\u003cp\u003eThe provided code demonstrates using \u003ccode\u003efirst()\u003c/code\u003e in both JavaScript and Python environments within the Google Earth Engine Code Editor and Colab.\u003c/p\u003e\n"]]],["The provided content describes the `.first()` method for an ImageCollection, which retrieves the initial Image within that collection. In JavaScript and Python examples, it's demonstrated by selecting the first image from the 'COPERNICUS/S2_SR' ImageCollection. The code then centers the map on this image, sets visualization parameters, displays it on the map, and prints the image's metadata. This method only takes the ImageCollection instance as input.\n"],null,["# ee.ImageCollection.first\n\n\u003cbr /\u003e\n\nReturns the first entry from a given collection.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|---------------------------|---------|\n| ImageCollection.first`()` | Image |\n\n| Argument | Type | Details |\n|-------------------------|-----------------|-------------------------------|\n| this: `imagecollection` | ImageCollection | The ImageCollection instance. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\nvar image = ee.ImageCollection('COPERNICUS/S2_SR').first();\nMap.centerObject(image, 8);\nvar vis = {bands: ['B4', 'B3', 'B2'], min: 0, max: 5000};\nMap.addLayer(image, vis, 'first of S2_SR');\n\n// Display the image metadata.\nprint(image);\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\nimage = ee.ImageCollection('COPERNICUS/S2_SR').first()\nm = geemap.Map()\nm.center_object(image, 8)\nvis = {'bands': ['B4', 'B3', 'B2'], 'min': 0, 'max': 5000}\nm.add_layer(image, vis, 'first of S2_SR')\ndisplay(m)\n\n# Display the image metadata.\ndisplay(image)\n```"]]