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Converts 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.
Note that geometries will be snapped to pixel centers.
The list of properties to copy from each input feature. Defaults to all non-system properties.
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.
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.
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.
geometries
Boolean, default: false
If true, the results will include a point geometry per sampled pixel. Otherwise, geometries will be omitted (saving memory).
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2024-07-13 UTC."],[[["\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```"]]
