ee.Image.selfMask

Updates an image's mask at all positions where the existing mask is not zero using the value of the image as the new mask value. The output image retains the metadata and footprint of the input image.
UsageReturns
Image.selfMask()Image
ArgumentTypeDetails
this: imageImageThe image to mask with itself.

Examples

Code Editor (JavaScript)

// A Sentinel-2 surface reflectance image.
var img = ee.Image('COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG');
var trueColorViz = {
  bands: ['B4', 'B3', 'B2'],
  min: 0,
  max: 2700,
  gamma: 1.3
};
print('Sentinel-2 image', img);
Map.setCenter(-122.36, 37.47, 10);
Map.addLayer(img, trueColorViz, 'Sentinel-2 image');

// Create a Boolean land mask from the SWIR1 band; water is value 0, land is 1.
var landMask = img.select('B11').gt(100);
print('Land mask', landMask);
Map.addLayer(landMask, {palette: ['blue', 'lightgreen']}, 'Land mask');

// Mask the land mask by itself; pixel values equal to 0 (water) become invalid.
var landMaskMasked = landMask.selfMask();
print('Land mask, masked', landMaskMasked);
Map.addLayer(landMaskMasked, {palette: ['gold']}, 'Land mask, masked');