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ee.Image.sampleRegions
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
將與一或多個區域相交的圖片像素 (以指定比例) 轉換為特徵,並以 FeatureCollection 形式傳回。每個輸出特徵都會有輸入圖片每個波段的屬性,以及從輸入特徵複製的任何指定屬性。
請注意,幾何圖形會對齊像素中心。
用量 | 傳回 |
---|
Image.sampleRegions(collection, properties, scale, projection, tileScale, geometries) | FeatureCollection |
引數 | 類型 | 詳細資料 |
---|
這個:image | 圖片 | 要取樣的圖片。 |
collection | FeatureCollection | 要取樣的區域。 |
properties | 清單,預設值為空值 | 要從每個輸入特徵複製的屬性清單。預設為所有非系統屬性。 |
scale | 浮點值,預設值為空值 | 投影的公尺名義比例,用於取樣。如未指定,系統會使用圖片第一個波段的比例。 |
projection | 投影,預設值:null | 要取樣的投影。如未指定,系統會使用圖片第一個波段的投影。如果除了比例外還指定了其他值,系統會重新調整為指定比例。 |
tileScale | 浮點值,預設值為 1 | 用於縮小聚合圖塊大小的縮放比例因數;使用較大的 tileScale (例如 2 或 4) 可能會啟用運算,導致記憶體不足。 |
geometries | 布林值,預設值為 false | 如果設為 true,結果會包含每個取樣像素的點幾何。否則系統會省略幾何圖形 (節省記憶體)。 |
範例
程式碼編輯器 (JavaScript)
// A Sentinel-2 surface reflectance image.
var img = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG');
Map.setCenter(-122.503881, 37.765588, 18);
Map.addLayer(img, {bands: ['B11', 'B8', 'B3'], min: 100, max: 4500}, 'img');
// A feature collection with two polygon regions each intersecting 36
// pixels at 10 m scale.
var fcPolygon = ee.FeatureCollection([
ee.Feature(ee.Geometry.Rectangle(
-122.50620929, 37.76502806, -122.50552264, 37.76556663), {id: 0}),
ee.Feature(ee.Geometry.Rectangle(
-122.50530270, 37.76565568, -122.50460533, 37.76619425), {id: 1})
]);
Map.addLayer(fcPolygon, {color: 'yellow'}, 'fcPolygon');
var fcPolygonSamp = img.sampleRegions({
collection: fcPolygon,
scale: 10,
geometries: true
});
// Note that 7 pixels are missing from the sample. If a pixel contains a masked
// band value it will be excluded from the sample. In this case, the TCI_B band
// is masked for each unsampled pixel.
print('A feature per pixel (at given scale) in each region', fcPolygonSamp);
Map.addLayer(fcPolygonSamp, {color: 'purple'}, 'fcPolygonSamp');
// A feature collection with two points intersecting two different pixels.
// This example is included to show the behavior for point geometries. In
// practice, if the feature collection is all points, ee.Image.reduceRegions
// should be used instead to save memory.
var fcPoint = ee.FeatureCollection([
ee.Feature(ee.Geometry.Point([-122.50309256, 37.76605006]), {id: 0}),
ee.Feature(ee.Geometry.Point([-122.50344661, 37.76560903]), {id: 1})
]);
Map.addLayer(fcPoint, {color: 'cyan'}, 'fcPoint');
var fcPointSamp = img.sampleRegions({
collection: fcPoint,
scale: 10
});
print('A feature per point', fcPointSamp);
Python 設定
請參閱
Python 環境頁面,瞭解 Python API 和如何使用 geemap
進行互動式開發。
import ee
import geemap.core as geemap
Colab (Python)
# A Sentinel-2 surface reflectance image.
img = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG')
m = geemap.Map()
m.set_center(-122.503881, 37.765588, 18)
m.add_layer(
img, {'bands': ['B11', 'B8', 'B3'], 'min': 100, 'max': 4500}, 'img'
)
display(m)
# A feature collection with two polygon regions each intersecting 36
# pixels at 10 m scale.
fc_polygon = ee.FeatureCollection([
ee.Feature(
ee.Geometry.Rectangle(
-122.50620929, 37.76502806, -122.50552264, 37.76556663
),
{'id': 0},
),
ee.Feature(
ee.Geometry.Rectangle(
-122.50530270, 37.76565568, -122.50460533, 37.76619425
),
{'id': 1},
),
])
m.add_layer(fc_polygon, {'color': 'yellow'}, 'fc_polygon')
fc_polygon_samp = img.sampleRegions(
collection=fc_polygon, scale=10, geometries=True
)
# Note that 7 pixels are missing from the sample. If a pixel contains a masked
# band value it will be excluded from the sample. In this case, the TCI_B band
# is masked for each unsampled pixel.
display('A feature per pixel (at given scale) in each region', fc_polygon_samp)
m.add_layer(fc_polygon_samp, {'color': 'purple'}, 'fc_polygon_samp')
# A feature collection with two points intersecting two different pixels.
# This example is included to show the behavior for point geometries. In
# practice, if the feature collection is all points, ee.Image.reduceRegions
# should be used instead to save memory.
fc_point = ee.FeatureCollection([
ee.Feature(ee.Geometry.Point([-122.50309256, 37.76605006]), {'id': 0}),
ee.Feature(ee.Geometry.Point([-122.50344661, 37.76560903]), {'id': 1}),
])
m.add_layer(fc_point, {'color': 'cyan'}, 'fc_point')
fc_point_samp = img.sampleRegions(collection=fc_point, scale=10)
display('A feature per point', fc_point_samp)
除非另有註明,否則本頁面中的內容是採用創用 CC 姓名標示 4.0 授權,程式碼範例則為阿帕契 2.0 授權。詳情請參閱《Google Developers 網站政策》。Java 是 Oracle 和/或其關聯企業的註冊商標。
上次更新時間:2025-07-26 (世界標準時間)。
[null,null,["上次更新時間:2025-07-26 (世界標準時間)。"],[[["\u003cp\u003e\u003ccode\u003eImage.sampleRegions\u003c/code\u003e extracts pixel values from an image within specified regions, returning them as a FeatureCollection.\u003c/p\u003e\n"],["\u003cp\u003eEach output feature contains the band values of the input image for each sampled pixel, along with properties from the input features.\u003c/p\u003e\n"],["\u003cp\u003eGeometries are snapped to pixel centers, and you can control the sampling scale and projection.\u003c/p\u003e\n"],["\u003cp\u003eThe function provides options to include point geometries and adjust the tile scale for memory management.\u003c/p\u003e\n"],["\u003cp\u003eIf the input is a FeatureCollection of points, \u003ccode\u003eee.Image.reduceRegions\u003c/code\u003e is generally recommended for better memory efficiency.\u003c/p\u003e\n"]]],["The `Image.sampleRegions` method converts image pixels intersecting specified regions into a `FeatureCollection`. Each output feature contains properties from the input image bands and any designated input feature properties. Geometries are snapped to pixel centers. The sampling scale and projection can be specified; otherwise, the image's first band defaults are used. Optionally, geometries of the sampled pixels can be included, and tile scaling can be used for memory management.\n"],null,["# ee.Image.sampleRegions\n\nConverts each pixel of an image (at a given scale) that intersects one or more regions to a Feature, returning them as a FeatureCollection. Each output feature will have one property per band of the input image, as well as any specified properties copied from the input feature.\n\n\u003cbr /\u003e\n\nNote that geometries will be snapped to pixel centers.\n\n| Usage | Returns |\n|-----------------------------------------------------------------------------------------------------------------|-------------------|\n| Image.sampleRegions`(collection, `*properties* `, `*scale* `, `*projection* `, `*tileScale* `, `*geometries*`)` | FeatureCollection |\n\n| Argument | Type | Details |\n|---------------|---------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| this: `image` | Image | The image to sample. |\n| `collection` | FeatureCollection | The regions to sample over. |\n| `properties` | List, default: null | The list of properties to copy from each input feature. Defaults to all non-system properties. |\n| `scale` | Float, default: null | A nominal scale in meters of the projection to sample in. If unspecified, the scale of the image's first band is used. |\n| `projection` | Projection, default: null | The projection in which to sample. If unspecified, the projection of the image's first band is used. If specified in addition to scale, rescaled to the specified scale. |\n| `tileScale` | Float, default: 1 | A scaling factor used to reduce aggregation tile size; using a larger tileScale (e.g., 2 or 4) may enable computations that run out of memory with the default. |\n| `geometries` | Boolean, default: false | If true, the results will include a point geometry per sampled pixel. Otherwise, geometries will be omitted (saving memory). |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// A Sentinel-2 surface reflectance image.\nvar img = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG');\nMap.setCenter(-122.503881, 37.765588, 18);\nMap.addLayer(img, {bands: ['B11', 'B8', 'B3'], min: 100, max: 4500}, 'img');\n\n// A feature collection with two polygon regions each intersecting 36\n// pixels at 10 m scale.\nvar fcPolygon = ee.FeatureCollection([\n ee.Feature(ee.Geometry.Rectangle(\n -122.50620929, 37.76502806, -122.50552264, 37.76556663), {id: 0}),\n ee.Feature(ee.Geometry.Rectangle(\n -122.50530270, 37.76565568, -122.50460533, 37.76619425), {id: 1})\n]);\nMap.addLayer(fcPolygon, {color: 'yellow'}, 'fcPolygon');\n\nvar fcPolygonSamp = img.sampleRegions({\n collection: fcPolygon,\n scale: 10,\n geometries: true\n});\n// Note that 7 pixels are missing from the sample. If a pixel contains a masked\n// band value it will be excluded from the sample. In this case, the TCI_B band\n// is masked for each unsampled pixel.\nprint('A feature per pixel (at given scale) in each region', fcPolygonSamp);\nMap.addLayer(fcPolygonSamp, {color: 'purple'}, 'fcPolygonSamp');\n\n// A feature collection with two points intersecting two different pixels.\n// This example is included to show the behavior for point geometries. In\n// practice, if the feature collection is all points, ee.Image.reduceRegions\n// should be used instead to save memory.\nvar fcPoint = ee.FeatureCollection([\n ee.Feature(ee.Geometry.Point([-122.50309256, 37.76605006]), {id: 0}),\n ee.Feature(ee.Geometry.Point([-122.50344661, 37.76560903]), {id: 1})\n]);\nMap.addLayer(fcPoint, {color: 'cyan'}, 'fcPoint');\n\nvar fcPointSamp = img.sampleRegions({\n collection: fcPoint,\n scale: 10\n});\nprint('A feature per point', fcPointSamp);\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\n# A Sentinel-2 surface reflectance image.\nimg = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG')\nm = geemap.Map()\nm.set_center(-122.503881, 37.765588, 18)\nm.add_layer(\n img, {'bands': ['B11', 'B8', 'B3'], 'min': 100, 'max': 4500}, 'img'\n)\ndisplay(m)\n\n# A feature collection with two polygon regions each intersecting 36\n# pixels at 10 m scale.\nfc_polygon = ee.FeatureCollection([\n ee.Feature(\n ee.Geometry.Rectangle(\n -122.50620929, 37.76502806, -122.50552264, 37.76556663\n ),\n {'id': 0},\n ),\n ee.Feature(\n ee.Geometry.Rectangle(\n -122.50530270, 37.76565568, -122.50460533, 37.76619425\n ),\n {'id': 1},\n ),\n])\nm.add_layer(fc_polygon, {'color': 'yellow'}, 'fc_polygon')\n\nfc_polygon_samp = img.sampleRegions(\n collection=fc_polygon, scale=10, geometries=True\n)\n# Note that 7 pixels are missing from the sample. If a pixel contains a masked\n# band value it will be excluded from the sample. In this case, the TCI_B band\n# is masked for each unsampled pixel.\ndisplay('A feature per pixel (at given scale) in each region', fc_polygon_samp)\nm.add_layer(fc_polygon_samp, {'color': 'purple'}, 'fc_polygon_samp')\n\n# A feature collection with two points intersecting two different pixels.\n# This example is included to show the behavior for point geometries. In\n# practice, if the feature collection is all points, ee.Image.reduceRegions\n# should be used instead to save memory.\nfc_point = ee.FeatureCollection([\n ee.Feature(ee.Geometry.Point([-122.50309256, 37.76605006]), {'id': 0}),\n ee.Feature(ee.Geometry.Point([-122.50344661, 37.76560903]), {'id': 1}),\n])\nm.add_layer(fc_point, {'color': 'cyan'}, 'fc_point')\n\nfc_point_samp = img.sampleRegions(collection=fc_point, scale=10)\ndisplay('A feature per point', fc_point_samp)\n```"]]