ee.Geometry.BBox.simplify

  • Simplifies the geometry to a specified error margin, potentially overriding user-requested accuracy for consistent rendering.

  • Input geometries are requested with the algorithm's specified error margin, regardless of output accuracy requests.

  • Consistent rendering is achieved across zoom levels, but performance may be affected at lower zoom levels due to lack of simplification.

  • simplify() takes an optional maxError and proj argument to control simplification and projection.

 Simplifies the geometry to within a given error margin. Note that this does not respect the error margin requested by the consumer of this algorithm, unless maxError is explicitly specified to be null.

This overrides the default Earth Engine policy for propagating error margins, so regardless of the geometry accuracy requested from the output, the inputs will be requested with the error margin specified in the arguments to this algorithm. This results in consistent rendering at all zoom levels of a rendered vector map, but at lower zoom levels (i.e. zoomed out), the geometry won't be simplified, which may harm performance.

UsageReturns
BBox.simplify(maxError, proj)Geometry
ArgumentTypeDetails
this: geometryGeometryThe geometry to simplify.
maxErrorErrorMarginThe maximum amount of error by which the result may differ from the input.
projProjection, default: nullIf specified, the result will be in this projection. Otherwise it will be in the same projection as the input. If the error margin is in projected units, the margin will be interpreted as units of this projection.

Examples

Code Editor (JavaScript)

// Define a BBox object.
var bBox = ee.Geometry.BBox(-122.09, 37.42, -122.08, 37.43);

// Apply the simplify method to the BBox object.
var bBoxSimplify = bBox.simplify({'maxError': 1});

// Print the result to the console.
print('bBox.simplify(...) =', bBoxSimplify);

// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(bBox,
             {'color': 'black'},
             'Geometry [black]: bBox');
Map.addLayer(bBoxSimplify,
             {'color': 'red'},
             'Result [red]: bBox.simplify');

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)

# Define a BBox object.
bbox = ee.Geometry.BBox(-122.09, 37.42, -122.08, 37.43)

# Apply the simplify method to the BBox object.
bbox_simplify = bbox.simplify(maxError=1)

# Print the result.
display('bbox.simplify(...) =', bbox_simplify)

# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(bbox, {'color': 'black'}, 'Geometry [black]: bbox')
m.add_layer(bbox_simplify, {'color': 'red'}, 'Result [red]: bbox.simplify')
m