Computes a tile by performing an arbitrary computation on image data.
Returns:
The pixels as raw image data.
Usage | Returns |
ee.data.computePixels(params) | Object|Value |
Argument | Type | Details |
params | Object | An object containing parameters with the following possible values:
expression - The expression to compute.
fileFormat - The resulting file format. Defaults to png. See
ImageFileFormat
for the available formats. There are additional formats that convert
the downloaded object to a Python data object. These include:
NUMPY_NDARRAY , which converts to a structured NumPy
array.
grid - Parameters describing the pixel grid in which to fetch data.
Defaults to the native pixel grid of the data.
bandIds - If present, specifies a specific set of bands from which to get
pixels.
visualizationOptions - If present, a set of visualization options to apply
to produce an 8-bit RGB visualization of the data,
rather than returning the raw data.
workloadTag - User supplied tag to track this computation. |
Examples
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)
# Region of interest.
coords = [
-121.58626826832939,
38.059141484827485,
]
region = ee.Geometry.Point(coords)
# Sentinel-2 median composite.
image = (ee.ImageCollection('COPERNICUS/S2')
.filterBounds(region)
.filterDate('2020-04-01', '2020-09-01')
.median())
# Make a projection to discover the scale in degrees.
proj = ee.Projection('EPSG:4326').atScale(10).getInfo()
# Get scales out of the transform.
scale_x = proj['transform'][0]
scale_y = -proj['transform'][4]
# Make a request object.
request = {
'expression': image,
'fileFormat': 'PNG',
'bandIds': ['B4', 'B3', 'B2'],
'grid': {
'dimensions': {
'width': 640,
'height': 640
},
'affineTransform': {
'scaleX': scale_x,
'shearX': 0,
'translateX': coords[0],
'shearY': 0,
'scaleY': scale_y,
'translateY': coords[1]
},
'crsCode': proj['crs'],
},
'visualizationOptions': {'ranges': [{'min': 0, 'max': 3000}]},
}
image_png = ee.data.computePixels(request)
# Do something with the image...