ee.Image.subtract

Subtracts the second value from the first for each matched pair of bands in image1 and image2. If either image1 or image2 has only 1 band, then it is used against all the bands in the other image. If the images have the same number of bands, but not the same names, they're used pairwise in the natural order. The output bands are named for the longer of the two inputs, or if they're equal in length, in image1's order. The type of the output pixels is the union of the input types.

Usage	Returns
`Image.subtract(image2)`	Image

Argument	Type	Details
this: `image1`	Image	The image from which the left operand bands are taken.
`image2`	Image	The image from which the right operand bands are taken.

Examples

Code Editor (JavaScript)

// A Sentinel-2 surface reflectance image.
var img = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG');

// Subset two image bands and display them on the map.
var swir1 = img.select('B11');
var swir2 = img.select('B12');
Map.setCenter(-122.276, 37.456, 12);
Map.addLayer(swir1, {min: 0, max: 3000}, 'swir1');
Map.addLayer(swir2, {min: 0, max: 3000}, 'swir2');

// The following examples demonstrate ee.Image arithmetic methods using two
// single-band ee.Image inputs.
var addition = swir1.add(swir2);
Map.addLayer(addition, {min: 100, max: 6000}, 'addition');

var subtraction = swir1.subtract(swir2);
Map.addLayer(subtraction, {min: 0, max: 1500}, 'subtraction');

var multiplication = swir1.multiply(swir2);
Map.addLayer(multiplication, {min: 1.9e5, max: 9.4e6}, 'multiplication');

var division = swir1.divide(swir2);
Map.addLayer(division, {min: 0, max: 3}, 'division');

var remainder = swir1.mod(swir2);
Map.addLayer(remainder, {min: 0, max: 1500}, 'remainder');

// If a number input is provided as the second argument, it will automatically
// be promoted to an ee.Image object, a convenient shorthand for constants.
var exponent = swir1.pow(3);
Map.addLayer(exponent, {min: 0, max: 2e10}, 'exponent');

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)

# A Sentinel-2 surface reflectance image.
img = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG')

# Subset two image bands and display them on the map.
swir_1 = img.select('B11')
swir_2 = img.select('B12')
m = geemap.Map()
m.set_center(-122.276, 37.456, 12)
m.add_layer(swir_1, {'min': 0, 'max': 3000}, 'swir_1')
m.add_layer(swir_2, {'min': 0, 'max': 3000}, 'swir_2')

# The following examples demonstrate ee.Image arithmetic methods using two
# single-band ee.Image inputs.
addition = swir_1.add(swir_2)
m.add_layer(addition, {'min': 100, 'max': 6000}, 'addition')

subtraction = swir_1.subtract(swir_2)
m.add_layer(subtraction, {'min': 0, 'max': 1500}, 'subtraction')

multiplication = swir_1.multiply(swir_2)
m.add_layer(multiplication, {'min': 1.9e5, 'max': 9.4e6}, 'multiplication')

division = swir_1.divide(swir_2)
m.add_layer(division, {'min': 0, 'max': 3}, 'division')

remainder = swir_1.mod(swir_2)
m.add_layer(remainder, {'min': 0, 'max': 1500}, 'remainder')

# If a number input is provided as the second argument, it will automatically
# be promoted to an ee.Image object, a convenient shorthand for constants.
exponent = swir_1.pow(3)
m.add_layer(exponent, {'min': 0, 'max': 2e10}, 'exponent')
m