Nearest Neighbour Pixel Value Google Earth Engine

Question

I want to attach the values from one raster to another raster. Using simple band math I can multiply the value of the base raster which is the presence of mangroves and therefore 1 or masked by the value of the other raster, which is the change in water from the Pekel water layer. This works for where both rasters have a value but where the Pekel layer is masked I would want the value in the mangrove layer to be the nearest pixel in Pekel layer.

//import Pekel data
var gsw = ee.Image('JRC/GSW1_0/GlobalSurfaceWater');
var change = gsw.select("change_abs");


//import Mangroves of the World   
var mangrove = ee.Image(ee.ImageCollection('LANDSAT/MANGROVE_FORESTS').first()); 

//////////////////////////////////////////////////////////////
// Constants
//////////////////////////////////////////////////////////////

var VIS_CHANGE = {
    min:-100,
    max:100,
    palette: ['red', 'black', 'limegreen']
};


var MANGROVE_COL = {
  palette: ['orange']
};

//////////////////////////////////////////////////////////////
// Calculations
//////////////////////////////////////////////////////////////

var combine = mangrove.select('1').multiply(change.select('change_abs'))

//////////////////////////////////////////////////////////////
// Map Layers
//////////////////////////////////////////////////////////////

Map.addLayer({
  eeObject: mangrove, 
  visParams: MANGROVE_COL, 
  name: 'mangrove extent', 
  shown: false
});

//Change in water intensity
Map.addLayer({
  eeObject: change,
  visParams: VIS_CHANGE,
  name: 'occurrence change intensity', 
  shown: false
});




//Change in water intensity
Map.addLayer({
  eeObject: combine,
  visParams: VIS_CHANGE,
  name: 'occurrence change intensity in mangrove', 
  shown: true
});

Answer 1

You can unmask() using another image. Masked values in the first image will be replaced by the values in the second.