def unbuffered(shape):
projected = project(shape, "epsg:4326", "epsg:3857")
# if int(round(projected.area)) < 100:
# return None
unbuffered = projected.buffer(-1 * args.threshold)
unprojected = project(unbuffered, "epsg:3857", "epsg:4326")
return unprojected
def unbuffered(shape):
projected = project(shape, "epsg:4326", "epsg:3857")
if int(round(projected.area)) < 200:
return None
# unbuffered = projected.buffer(-0.2 * args.threshold)
unprojected = project(projected, "epsg:3857", "epsg:4326")
return unprojected
def buffered(shape):
projected = project(shape, "epsg:4326", "epsg:3857")
buffered = projected.buffer(args.threshold)
unprojected = project(buffered, "epsg:3857", "epsg:4326")
return unprojected
def main(args):
with open(args.features) as fp:
collection = geojson.load(fp)
shapes = [shapely.geometry.shape(feature["geometry"])
for feature in collection["features"]]
del collection
graph = UndirectedGraph()
idx = make_index(shapes)
def buffered(shape):
projected = project(shape, "epsg:4326", "epsg:3857")
buffered = projected.buffer(args.threshold)
unprojected = project(buffered, "epsg:3857", "epsg:4326")
return unprojected
def unbuffered(shape):
projected = project(shape, "epsg:4326", "epsg:3857")
# if int(round(projected.area)) < 100:
# return None
unbuffered = projected.buffer(-1 * args.threshold)
unprojected = project(unbuffered, "epsg:3857", "epsg:4326")
return unprojected
for i, shape in enumerate(tqdm(shapes, desc="Building graph", unit="shapes", ascii=True)):
embiggened = buffered(shape)
graph.add_edge(i, i)
nearest = [j for j in idx.intersection(
embiggened.bounds, objects=False) if i != j]
for t in nearest:
if embiggened.intersects(shapes[t]):
graph.add_edge(i, t)
components = list(graph.components())
assert sum([len(v) for v in components]) == len(
shapes), "components capture all shape indices"
features = []
for component in tqdm(components, desc="Merging components", unit="component", ascii=True):
embiggened = [buffered(shapes[v]) for v in component]
merged = unbuffered(union(embiggened))
if not merged:
continue
if merged.is_valid:
# Orient exterior ring of the polygon in counter-clockwise direction.
if isinstance(merged, shapely.geometry.polygon.Polygon):
merged = shapely.geometry.polygon.orient(merged, sign=1.0)
elif isinstance(merged, shapely.geometry.multipolygon.MultiPolygon):
merged = [shapely.geometry.polygon.orient(
geom, sign=1.0) for geom in merged.geoms]
merged = shapely.geometry.MultiPolygon(merged)
else:
print(
"Warning: merged feature is neither Polygon nor MultiPoylgon, skipping", file=sys.stderr)
continue
# equal-area projection; round to full m^2, we're not that precise anyway
area = int(round(project(merged, "epsg:4326", "epsg:3857").area))
if area < SETTING.MIN_BUILDING_AREA:
continue
feature = geojson.Feature(geometry=shapely.geometry.mapping(
merged)) # , properties={"area": area}
features.append(feature)
else:
print("Warning: merged feature is not valid, skipping",
file=sys.stderr)
collection = geojson.FeatureCollection(features)
with open(args.out, "w") as fp:
geojson.dump(collection, fp)
def unbuffered(shape):
projected = project(shape, "epsg:4326", "epsg:3395")
unbuffered = projected.buffer(-1 * args.threshold)
unprojected = project(unbuffered, "epsg:3395", "epsg:4326")
return unprojected