ee.FeatureCollection.reduceToImage

Membuat gambar dari kumpulan fitur dengan menerapkan peredam pada properti yang dipilih dari semua fitur yang berpotongan dengan setiap piksel.

Penggunaan	Hasil
FeatureCollection.reduceToImage(properties, reducer)	Gambar

Argumen	Jenis	Detail
ini: collection	FeatureCollection	Kumpulan fitur untuk berpotongan dengan setiap piksel output.
properties	Daftar	Properti yang akan dipilih dari setiap fitur dan diteruskan ke reducer.
reducer	Pengurang	Reducer untuk menggabungkan properti setiap fitur yang berpotongan ke dalam hasil akhir untuk disimpan dalam piksel.

Contoh

Code Editor (JavaScript)

// FeatureCollection of power plants in Belgium.
var fc = ee.FeatureCollection('WRI/GPPD/power_plants')
             .filter('country_lg == "Belgium"');

// Create an image from features; pixel values are determined from reduction of
// property values of the features intersecting each pixel.
var image = fc.reduceToImage({
  properties: ['gwh_estimt'],
  reducer: ee.Reducer.sum()
});

// The goal is to sum the electricity generated in 2015 for the power plants
// intersecting 10 km cells and view the result as a map layer.
// ee.FeatureCollection.reduceToImage does not allow the image projection to be
// set because it is waiting on downstream functions that include "crs",
// "scale", and "crsTransform" parameters to define it (e.g., Export.image.*).
// Here, we'll force the projection with ee.Image.reproject so the result can be
// viewed in the map. Note that using small scales with reproject while viewing
// large regions breaks the features that make Earth Engine fast and may result
// in poor performance and/or errors.
image = image.reproject('EPSG:3035', null, 10000);

// Display the image on the map.
Map.setCenter(4.3376, 50.947, 8);
Map.setLocked(true);
Map.addLayer(
    image.updateMask(image.gt(0)),
    {min: 0, max: 2000, palette: ['yellow', 'orange', 'red']},
    'Total estimated annual electricity generation, 2015');
Map.addLayer(fc, null, 'Belgian power plants');

Penyiapan Python

Lihat halaman Lingkungan Python untuk mengetahui informasi tentang Python API dan penggunaan geemap untuk pengembangan interaktif.

import ee
import geemap.core as geemap

Colab (Python)

# FeatureCollection of power plants in Belgium.
fc = ee.FeatureCollection('WRI/GPPD/power_plants').filter(
    'country_lg == "Belgium"'
)

# Create an image from features pixel values are determined from reduction of
# property values of the features intersecting each pixel.
image = fc.reduceToImage(properties=['gwh_estimt'], reducer=ee.Reducer.sum())

# The goal is to sum the electricity generated in 2015 for the power plants
# intersecting 10 km cells and view the result as a map layer.
# ee.FeatureCollection.reduceToImage does not allow the image projection to be
# set because it is waiting on downstream functions that include "crs",
# "scale", and "crsTransform" parameters to define it (e.g., Export.image.*).
# Here, we'll force the projection with ee.Image.reproject so the result can be
# viewed in the map. Note that using small scales with reproject while viewing
# large regions breaks the features that make Earth Engine fast and may result
# in poor performance and/or errors.
image = image.reproject('EPSG:3035', None, 10000)

# Display the image on the map.
m = geemap.Map()
m.set_center(4.3376, 50.947, 8)
m.add_layer(
    image.updateMask(image.gt(0)),
    {'min': 0, 'max': 2000, 'palette': ['yellow', 'orange', 'red']},
    'Total estimated annual electricity generation, 2015',
)
m.add_layer(fc, None, 'Belgian power plants')
m