AI-generated Key Takeaways
-
The
selfMask()method updates an image's mask using the image's own pixel values. -
The mask is updated at positions where the existing mask is not zero.
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The output image retains the original metadata and footprint.
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The
selfMask()method is called on anImageobject and returns a maskedImage.
| Usage | Returns |
|---|---|
Image.
selfMask
()
|
Image |
| Argument | Type | Details |
|---|---|---|
|
this:
image
|
Image | The 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' );
import ee import geemap.core as geemap
Colab (Python)
# A Sentinel-2 surface reflectance image. img = ee . Image ( 'COPERNICUS/S2_SR/20210109T185751_20210109T185931_T10SEG' ) true_color_viz = { 'bands' : [ 'B4' , 'B3' , 'B2' ], 'min' : 0 , 'max' : 2700 , 'gamma' : 1.3 , } display ( 'Sentinel-2 image' , img ) m = geemap . Map () m . set_center ( - 122.36 , 37.47 , 10 ) m . add_layer ( img , true_color_viz , 'Sentinel-2 image' ) # Create a Boolean land mask from the SWIR1 band water is value 0, land is 1. land_mask = img . select ( 'B11' ) . gt ( 100 ) display ( 'Land mask' , land_mask ) m . add_layer ( land_mask , { 'palette' : [ 'blue' , 'lightgreen' ]}, 'Land mask' ) # Mask the land mask by itself pixel values equal to 0 (water) become invalid. land_mask_masked = land_mask . selfMask () display ( 'Land mask, masked' , land_mask_masked ) m . add_layer ( land_mask_masked , { 'palette' : [ 'gold' ]}, 'Land mask, masked' ) m
