Polygonize a Raster¶

Polygonize a raster using gk.raster.polygonizeRaster(raster). This function converts raster cells into polygon geometries.

In [1]:

# extract value at a given location by interpolating
import pathlib
import geokit.core.raster
import geokit.core.srs
import geokit.core.geom
import numpy as np
import matplotlib.pyplot as plt

# extract value at a given location by interpolating import pathlib import geokit.core.raster import geokit.core.srs import geokit.core.geom import numpy as np import matplotlib.pyplot as plt

In [2]:

# create a raster from a matrix
raster_matrix = np.array(
    [
        [1, 2, 3],
        [2, 2, 2],
        [3, 2, 1],
    ]
)

ras = geokit.core.raster.createRaster(
    bounds=(5, 48, 8, 51),
    pixelWidth=1,
    pixelHeight=1,
    data=raster_matrix,
    srs=geokit.core.srs.EPSG4326,
)
# polygonize a raster
ras_boolean = geokit.core.raster.createRasterLike(source=ras, data=raster_matrix == 2)

polygonized_geoms = geokit.core.raster.polygonizeRaster(ras_boolean)

# create a raster from a matrix raster_matrix = np.array( [ [1, 2, 3], [2, 2, 2], [3, 2, 1], ] ) ras = geokit.core.raster.createRaster( bounds=(5, 48, 8, 51), pixelWidth=1, pixelHeight=1, data=raster_matrix, srs=geokit.core.srs.EPSG4326, ) # polygonize a raster ras_boolean = geokit.core.raster.createRasterLike(source=ras, data=raster_matrix == 2) polygonized_geoms = geokit.core.raster.polygonizeRaster(ras_boolean)

In [3]:

# draw polygonized geom
geokit.core.geom.drawGeoms(polygonized_geoms.geom[polygonized_geoms.value == 1], figsize=(6, 6))
plt.show()

# draw polygonized geom geokit.core.geom.drawGeoms(polygonized_geoms.geom[polygonized_geoms.value == 1], figsize=(6, 6)) plt.show()

In [4]:

# draw polygonized geom with buffer
geokit.core.geom.drawGeoms(
    polygonized_geoms.geom[polygonized_geoms.value == 1].iloc[0].Buffer(0.5),
    figsize=(6, 6),
)
plt.show()

# draw polygonized geom with buffer geokit.core.geom.drawGeoms( polygonized_geoms.geom[polygonized_geoms.value == 1].iloc[0].Buffer(0.5), figsize=(6, 6), ) plt.show()