def test_square_pass_affine(self):
"""Test both forward and inverse transforms when passed affine obj."""
xform_result = convert_poly_coords(square, affine_obj=aff)
assert xform_result == forward_result
rev_xform_result = convert_poly_coords(square,
affine_obj=aff,
inverse=True)
assert rev_xform_result == reverse_result
def test_square_pass_list(self):
"""Test forward and reverse affine transform when passed a list."""
fwd_xform_result = convert_poly_coords(square,
affine_obj=affine_list)
assert fwd_xform_result == forward_result
rev_xform_result = convert_poly_coords(square,
affine_obj=affine_list,
inverse=True)
assert rev_xform_result == reverse_result
def rareplanes_tiler(untiled_image_dir,
untiled_geojson_dir,
image_tiles_out_dir,
geojson_tiles_out_dir,
tile_size=512,
overlap=0.2,
min_obj_area_m=100,
min_obj_perc=0.25):
"""Function to tile a set of images into smaller square chunks with embedded georeferencing info
allowing an end user to specify the size of the tile, the overlap of each tile, and when to discard
a tile if it contains blank datasets.
Args:
- untiled_image_dir (str): directory contained full untiled satellite images
- untiled_geojson_dir (str): directory for full untiled geojson fukes
- image_tiles_out_dir (str): output directory for tiled imagery.
- geojson_tiles_out_dir (str): output directory for tiled geojson files
- tile_size (int): tile height and width
- overlap (float): amount of overlap of each tile in float format. Should range between 0 and <1.
- min_obj_area_m (float): minimum area in m^2 of truncated object to be keep as a valid annotation
- min_obj_perc (float): minimum visible ratio of truncated object to be keep as a valid annotatio.
Should range between 0 and 1.
"""
# some hardcoded stuff
output_channels = [1, 2, 3]
ext = ".tif"
# create the output directories
os.makedirs(image_tiles_out_dir, exist_ok=True)
os.makedirs(geojson_tiles_out_dir, exist_ok=True)
os.chdir(untiled_image_dir)
# list the images
images = glob.glob("*" + ext)
tile_size = int(tile_size)
for im in tqdm(images):
raster = gdal.Open(os.path.abspath(im))
geojson = os.path.join(untiled_geojson_dir,
im.split(ext)[0] + ".geojson")
in_gdf = gpd.read_file(geojson)
in_gdf['area'] = in_gdf['geometry'].apply(lambda x: x.area)
width = int(raster.RasterXSize)
height = int(raster.RasterYSize)
count = 0
# loop through the tiles
for i in tqdm(range(0, width, int(tile_size * (1 - overlap)))):
for j in range(0, height, int(tile_size * (1 - overlap))):
srcWin_chip = [i, j, tile_size, tile_size]
bbox = box(i, j, i + tile_size, j + tile_size)
chip = convert_poly_coords(bbox, raster_src=im)
gdf = clip_gdf(in_gdf, chip)
# check if there is an object in that tile
if len(gdf) > 0:
gdf['new_area'] = gdf['area'] * gdf['partialDec']
gdf = gdf[(((gdf['partialDec'] <= min_obj_perc) &
(gdf['new_area'] >= min_obj_area_m)) |
(gdf['partialDec'] > min_obj_perc))]
gdf.drop(columns=['origarea', 'origlen'], inplace=True)
# remove small / highly truncated objects
if len(gdf) > 0:
count += 1
tileout = image_tiles_out_dir + "/" + \
im.split(ext)[0] + "_tile_" + str(count) + ".png"
geojson_out = geojson_tiles_out_dir + "/" + \
im.split(ext)[0] + "_tile_" + str(count) + ".geojson"
gdf.to_file(geojson_out, driver="GeoJSON")
output = gdal.Translate(tileout,
im,
srcWin=srcWin_chip,
bandList=output_channels)
del output
def test_square_pass_long_list(self):
"""Test forward affine transform when passed a full 9-element xform."""
fwd_xform_result = convert_poly_coords(
square, affine_obj=long_affine_list
)
assert fwd_xform_result == forward_result
def test_square_pass_gdal_list(self):
"""Test forward affine transform when passed a list in gdal order."""
fwd_xform_result = convert_poly_coords(square,
affine_obj=gdal_affine_list
)
assert fwd_xform_result == forward_result
def test_square_pass_raster(self):
"""Test forward affine transform when passed a raster reference."""
raster_src = os.path.join(data_dir, 'sample_geotiff.tif')
xform_result = convert_poly_coords(square, raster_src=raster_src)
assert xform_result == forward_result