OpenBuildingMap Global Building Footprints with Semantic Information¶

// Load the tile grid to explore coverage and metadata
var grid = ee.FeatureCollection('projects/sat-io/open-datasets/OPEN-BUILDING-MAPS/open_buildings_grid');

// Example: Load a specific tile (Berlin area - tile 120301)
var buildings = ee.FeatureCollection('projects/sat-io/open-datasets/OPEN-BUILDING-MAPS/tiles/building_311230');

// Print tile metadata from grid
var tile_info = grid.filter(ee.Filter.eq('quadkey', '311230')).first();
print('Tile Information:', tile_info);

// Filter buildings with known occupancy types
var buildings_with_occupancy = buildings.filter(ee.Filter.neq('occupancy', 'UNK'));
print('Buildings with occupancy:', buildings_with_occupancy.size());

// Filter buildings with height information
var buildings_with_height = buildings.filter(
  ee.Filter.and(
    ee.Filter.neq('height', ''),
    ee.Filter.neq('height', null)
  )
);
print('Buildings with height:', buildings_with_height.size());

// Visualize buildings by occupancy type
var occupancyColors = {
  'RES': '3498db',   // Residential - blue
  'RES1': '3498db',  // Single-family residential
  'RES2': '2980b9',  // Multi-family residential
  'COM': 'e74c3c',   // Commercial - red
  'MIX': '9b59b6',   // Mixed use - purple
  'IND': 'f39c12',   // Industrial - orange
  'AGR': '27ae60',   // Agricultural - green
  'ASS': '16a085',   // Assembly - teal
  'GOV': '34495e',   // Government - dark gray
  'EDU': 'e67e22',   // Education - orange
  'UNK': 'bdc3c7'    // Unknown - light gray
};

// Function to style buildings by occupancy type
function styleByOccupancy(occupancyType, color) {
  var filtered = buildings.filter(ee.Filter.stringStartsWith('occupancy', occupancyType));
  return filtered.style({
    color: color,
    fillColor: color + '80',  // Add transparency
    width: 1
  });
}

// Add layers for major occupancy types
Object.keys(occupancyColors).forEach(function(type) {
  var layer = styleByOccupancy(type, occupancyColors[type]);
  Map.addLayer(layer, {}, type + ' Buildings', false);
});

// Visualize buildings by data source
var osm_buildings = buildings.filter(ee.Filter.eq('source', 'OSM'));
var google_buildings = buildings.filter(ee.Filter.eq('source', 'Google'));
var microsoft_buildings = buildings.filter(ee.Filter.eq('source', 'Microsoft'));

Map.addLayer(osm_buildings.style({color: '2ecc71', width: 1}), {}, 'OpenStreetMap', false);
Map.addLayer(google_buildings.style({color: 'e74c3c', width: 1}), {}, 'Google', false);
Map.addLayer(microsoft_buildings.style({color: '3498db', width: 1}), {}, 'Microsoft', false);

// Example: Analyze residential buildings
var residential = buildings.filter(ee.Filter.stringStartsWith('occupancy', 'RES'));
Map.addLayer(residential.style({color: '3498db', fillColor: '3498db80', width: 1}),
             {}, 'Residential Buildings', true);

// Calculate statistics
print('Total buildings:', buildings.size());
print('Residential buildings:', residential.size());
print('OSM buildings:', osm_buildings.size());
print('Google buildings:', google_buildings.size());
print('Microsoft buildings:', microsoft_buildings.size());

// Create legend for occupancy types
var legend = ui.Panel({
  style: {
    position: 'bottom-left',
    padding: '8px 15px',
    backgroundColor: 'white'
  }
});

var legendTitle = ui.Label({
  value: 'Building Occupancy Types',
  style: {
    fontWeight: 'bold',
    fontSize: '16px',
    margin: '0 0 4px 0',
    padding: '0'
  }
});
legend.add(legendTitle);

// Add color entries to legend
Object.keys(occupancyColors).forEach(function(type) {
  var colorBox = ui.Label({
    style: {
      backgroundColor: '#' + occupancyColors[type],
      padding: '8px',
      margin: '0 8px 0 0'
    }
  });

  var description = ui.Label({
    value: type,
    style: {margin: '0 0 4px 0'}
  });

  var panel = ui.Panel({
    widgets: [colorBox, description],
    layout: ui.Panel.Layout.Flow('horizontal')
  });

  legend.add(panel);
});

Map.add(legend);

// Center on tile location (adjust coordinates for your tile)
Map.setCenter(buildings.first());