" image.select(bands).sampleRegions is not a function error. what must i do?

问题

I am trying to conduct a lulc classification on google earth engine using landsat5 data for 2000, but every time it is showing me the error:

image.select(bands).sampleRegions is not a function

var shp = ee.FeatureCollection(mws)

 Map.addLayer(shp, {}, 'My Polygon')

 var pol = ee.FeatureCollection(poly2000)

 Map.addLayer(pol, {} )


  //landcover for 2000//
   var dataset = ee.ImageCollection("LANDSAT/LT05/C01/T1_TOA")
              .filterBounds(roi1)
              .filterDate('2000-01-01', '2000-01-31')
              .map(function(image){return image.clip(mws)});
              
            
            
    var trueColor432 = dataset.select(['B4', 'B3', 'B2']);
    var trueColor432Vis = {};
    Map.setCenter(88.41713038056656,26.861987108179317);
    Map.addLayer(trueColor432, trueColor432Vis, 'True Color (432)'); 

   var image = trueColor432;


   // merging sample points together
   var landcover = forest.merge(water).merge(clearing).merge(built_up);
       print(landcover);


     // selecting bands
     var bands= ['B2','B3','B4'];

    //sampling the input imagery to get a featurecollection of a training data

    var training = image.select(bands).sampleRegions({
        collection: landcover,
        properties: ['landcover'],
         scale: 30
    });


   //training the classifier
   var classifier= ee.Classifier.svm().train({
        features: training,
        classProperty : 'landcover',
        inputProperties: bands
   });

  //classifying the input imagery
  var classified= image.select(bands).classify(classifier);

回答1:

sampleRegions samples the pixels of an image: https://developers.google.com/earth-engine/apidocs/ee-image-sampleregions

Maybe adding .toBands() works?

var training = image.toBands().select(bands).sampleRegions({
    collection: landcover,
    properties: ['landcover'],
     scale: 30
});

来源：https://stackoverflow.com/questions/63984413/image-selectbands-sampleregions-is-not-a-function-error-what-must-i-do

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