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I have a classification that goes from 1985 to 2020. I would like to reclassify them all to values ​​of 0 and 1, that is, vegetation and not vegetation. I tried using the .remap() function, but I must specify a band and it only works for one.

var asset = "projects/mapbiomas-workspace/public/collection6/mapbiomas_collection60_integration_v1";
var mapbiomas = ee.Image(asset).selfMask();

var or = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30]
var new = [1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]

var mapbiomas_1985 = mapbiomas.remap({
 from: or,
 to: new,
 defaultValue: 0,
 bandName: 'classification_1985'
});
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1 Answer 1

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You need to map over the band names using remap function. For this purpose, use the same scheme for writting a new function

var asset = "projects/mapbiomas-workspace/public/collection6/mapbiomas_collection60_integration_v1";
var mapbiomas = ee.Image(asset).selfMask();

var oldvalues = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30];
var newvalues = [1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0];

var bnames = mapbiomas.bandNames();

var custom_fun = function(band){
  return mapbiomas.remap({
    from: oldvalues,
    to: newvalues,
    defaultValue: 0,
    bandName: band
  }).rename([band]);
};

var vegetation = bnames.map(custom_fun);

This function takes the band name while mapping. Then, if you want to obtain a ee.Image with the same band names, use this useful approach from Image collection to Single Image in Google Earth Engine

// from https://gis.stackexchange.com/a/295978/80215
var mergeBands = function(image, previous) {
  return ee.Image(previous).addBands(image);
};

var merged = vegetation.iterate(mergeBands, ee.Image([]));

I you want to obtain an ee.ImageCollection, just use ee.ImageCollection(vegetation) for converting the list.

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  • Thank you for helping me. The code seems to be working, but I must be doing something wrong. When I try this command, it gives me an error var vegetation2 = ee.ImageCollection(vegetation) Map.addLayer(vegetation2). Layer 4: Tile error: Expected a homogeneous image collection, but an image with incompatible bands was encountered: First image type: 1 bands ([classification_1985]). Current image type: 1 bands ([classification_1986]). Some bands might require explicit casts. Also, Map.addLayer(merged). return Line 191: Cannot add an object of type <ComputedObject> to the map.
    – Carlos Eduardo Carvalho
    Commented May 31, 2022 at 4:15
  • @CarlosEduardoCarvalho yep, it's because it's an ImageColelction with multiple single-bands images. You can use ee.ImageCollection(vegetation).toBands() for fixing it. And for merged, use ee.Image(merged)
    – aldo_tapia
    Commented May 31, 2022 at 12:43

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