04a_Post_Classification_Comparison

/**** Start of imports. If edited, may not auto-convert in the playground. ****/
var bangalore = ee.FeatureCollection("users/ujavalgandhi/public/bangalore_boundary"),
    urban = 
    /* color: #cad6c9 */
    /* shown: false */
    ee.FeatureCollection(
        [ee.Feature(
            ee.Geometry.Point([77.65618319730623, 12.95477448092164]),
            {
              "landcover": 0,
              "system:index": "0"
            }),
        ee.Feature(
            ee.Geometry.Point([77.65865082959994, 12.954586277198294]),
            {
              "landcover": 0,
              "system:index": "1"
            }),
        ee.Feature(
            ee.Geometry.Point([77.63830895643099, 12.955150887941738]),
            {
              "landcover": 0,
              "system:index": "2"
            }),
        ee.Feature(
            ee.Geometry.Point([77.66609664182528, 12.94988113790161]),
            {
              "landcover": 0,
              "system:index": "3"
            }),
        ee.Feature(
            ee.Geometry.Point([77.66375775556429, 12.901946395056886]),
            {
              "landcover": 0,
              "system:index": "4"
            }),
        ee.Feature(
            ee.Geometry.Point([77.65888686399325, 12.89370537764819]),
            {
              "landcover": 0,
              "system:index": "5"
            }),
        ee.Feature(
            ee.Geometry.Point([77.65365119199618, 12.896257193774513]),
            {
              "landcover": 0,
              "system:index": "6"
            }),
        ee.Feature(
            ee.Geometry.Point([77.62019868116244, 12.879690841834488]),
            {
              "landcover": 0,
              "system:index": "7"
            }),
        ee.Feature(
            ee.Geometry.Point([77.52617116193636, 12.949504722919158]),
            {
              "landcover": 0,
              "system:index": "8"
            }),
        ee.Feature(
            ee.Geometry.Point([77.5341748736368, 12.950006609436077]),
            {
              "landcover": 0,
              "system:index": "9"
            }),
        ee.Feature(
            ee.Geometry.Point([77.52097840528353, 12.94268733095577]),
            {
              "landcover": 0,
              "system:index": "10"
            }),
        ee.Feature(
            ee.Geometry.Point([77.53140683393343, 12.936183448914932]),
            {
              "landcover": 0,
              "system:index": "11"
            }),
        ee.Feature(
            ee.Geometry.Point([77.53735060911043, 12.932983727663112]),
            {
              "landcover": 0,
              "system:index": "12"
            })]),
    bare = 
    /* color: #aa7233 */
    /* shown: false */
    ee.FeatureCollection(
        [ee.Feature(
            ee.Geometry.Point([77.57875318746432, 12.90030448811505]),
            {
              "landcover": 1,
              "system:index": "0"
            }),
        ee.Feature(
            ee.Geometry.Point([77.5725885921923, 12.900400939536988]),
            {
              "landcover": 1,
              "system:index": "1"
            }),
        ee.Feature(
            ee.Geometry.Point([77.49744362980495, 12.922142137826711]),
            {
              "landcover": 1,
              "system:index": "2"
            }),
        ee.Feature(
            ee.Geometry.Point([77.49586649090419, 12.923512017657885]),
            {
              "landcover": 1,
              "system:index": "3"
            }),
        ee.Feature(
            ee.Geometry.Point([77.51070317426908, 12.987672000516854]),
            {
              "landcover": 1,
              "system:index": "4"
            }),
        ee.Feature(
            ee.Geometry.Point([77.62705455241222, 13.020352510846644]),
            {
              "landcover": 1,
              "system:index": "5"
            }),
        ee.Feature(
            ee.Geometry.Point([77.60701308665294, 13.023070275607665]),
            {
              "landcover": 1,
              "system:index": "6"
            }),
        ee.Feature(
            ee.Geometry.Point([77.64254458593136, 12.921107680565637]),
            {
              "landcover": 1,
              "system:index": "7"
            }),
        ee.Feature(
            ee.Geometry.Point([77.63974435971981, 12.919444985009568]),
            {
              "landcover": 1,
              "system:index": "8"
            }),
        ee.Feature(
            ee.Geometry.Point([77.66746775692845, 12.935331697011328]),
            {
              "landcover": 1,
              "system:index": "9"
            })]),
    water = 
    /* color: #0b4a8b */
    /* shown: false */
    ee.FeatureCollection(
        [ee.Feature(
            ee.Geometry.Point([77.58402702188951, 12.946465216050397]),
            {
              "landcover": 2,
              "system:index": "0"
            }),
        ee.Feature(
            ee.Geometry.Point([77.58241769648058, 12.944980444410998]),
            {
              "landcover": 2,
              "system:index": "1"
            }),
        ee.Feature(
            ee.Geometry.Point([77.56014463282091, 12.952027802976799]),
            {
              "landcover": 2,
              "system:index": "2"
            }),
        ee.Feature(
            ee.Geometry.Point([77.61788722849352, 12.909343273988116]),
            {
              "landcover": 2,
              "system:index": "3"
            }),
        ee.Feature(
            ee.Geometry.Point([77.67170307016832, 12.935778845503677]),
            {
              "landcover": 2,
              "system:index": "4"
            })]),
    vegetation = 
    /* color: #4dff5e */
    /* shown: false */
    ee.FeatureCollection(
        [ee.Feature(
            ee.Geometry.Point([77.5929834739004, 12.973819098281412]),
            {
              "landcover": 3,
              "system:index": "0"
            }),
        ee.Feature(
            ee.Geometry.Point([77.5915243521963, 12.972020838933782]),
            {
              "landcover": 3,
              "system:index": "1"
            }),
        ee.Feature(
            ee.Geometry.Point([77.58681439316615, 12.948882773171434]),
            {
              "landcover": 3,
              "system:index": "2"
            }),
        ee.Feature(
            ee.Geometry.Point([77.58470259216357, 12.952709641880457]),
            {
              "landcover": 3,
              "system:index": "3"
            }),
        ee.Feature(
            ee.Geometry.Point([77.58338294532824, 12.913978183843149]),
            {
              "landcover": 3,
              "system:index": "4"
            }),
        ee.Feature(
            ee.Geometry.Point([77.58053458317988, 12.923805025122903]),
            {
              "landcover": 3,
              "system:index": "5"
            }),
        ee.Feature(
            ee.Geometry.Point([77.57196240215771, 13.010018094770263]),
            {
              "landcover": 3,
              "system:index": "6"
            }),
        ee.Feature(
            ee.Geometry.Point([77.56953768520825, 13.021422529521482]),
            {
              "landcover": 3,
              "system:index": "7"
            })]);
/***** End of imports. If edited, may not auto-convert in the playground. *****/
var geometry = bangalore.geometry();
Map.centerObject(geometry);

var s2 = ee.ImageCollection('COPERNICUS/S2_SR');
var rgbVis = {
  min: 0.0,
  max: 3000,
  bands: ['B4', 'B3', 'B2'], 
};

// 2019 Jan
var filtered = s2
  .filter(ee.Filter.date('2019-01-01', '2019-02-01'))
  .filter(ee.Filter.bounds(geometry))
  .select('B.*');

var before = filtered.median();
// Display the input composite.
Map.addLayer(before.clip(geometry), rgbVis, 'before');

var training = urban.merge(bare).merge(water).merge(vegetation);

// Overlay the point on the image to get training data.
var training = before.sampleRegions({
  collection: training, 
  properties: ['landcover'], 
  scale: 10
});

// Train a classifier.
var classifier = ee.Classifier.smileRandomForest(50).train({
  features: training,  
  classProperty: 'landcover', 
  inputProperties: before.bandNames()
});

// // Classify the image.
var beforeClassified = before.classify(classifier);
var palette = ['#cc6d8f', '#ffc107', '#1e88e5', '#004d40' ];
var classifiedVis = {min: 0, max: 3, palette: palette};
Map.addLayer(beforeClassified.clip(geometry), classifiedVis, 'before_classified');


// 2020 Jan
var after = s2
  .filter(ee.Filter.date('2020-01-01', '2020-02-01'))
  .filter(ee.Filter.bounds(geometry))
  .select('B.*')
  .median();
  
Map.addLayer(after.clip(geometry), rgbVis, 'after');

// Classify the image.
var afterClassified= after.classify(classifier);
Map.addLayer(afterClassified.clip(geometry), classifiedVis, 'after_classified');