OpenDroneMap-WebODM/app/raster_utils.py

50 wiersze
1.6 KiB
Python

# Export a raster index after applying a band expression
import rasterio
import re
import numpy as np
import numexpr as ne
from rasterio.enums import ColorInterp
from rio_tiler.utils import has_alpha_band
def export_raster_index(input, expression, output):
with rasterio.open(input) as src:
profile = src.profile
profile.update(
dtype=rasterio.float32,
count=1,
nodata=-9999
)
bands_names = ["b{}".format(b) for b in tuple(sorted(set(re.findall(r"b(?P<bands>[0-9]{1,2})", expression))))]
rgb = expression.split(",")
indexes = tuple([int(b.replace("b", "")) for b in bands_names])
alpha_index = None
if has_alpha_band(src):
try:
alpha_index = src.colorinterp.index(ColorInterp.alpha) + 1
indexes += (alpha_index, )
except ValueError:
pass
data = src.read(indexes=indexes, out_dtype=np.float32)
arr = dict(zip(bands_names, data))
arr = np.array([np.nan_to_num(ne.evaluate(bloc.strip(), local_dict=arr)) for bloc in rgb])
# Set nodata values
index_band = arr[0]
if alpha_index is not None:
# -1 is the last band = alpha
index_band[data[-1] == 0] = -9999
# Remove infinity values
index_band[index_band>1e+30] = -9999
index_band[index_band<-1e+30] = -9999
# Make sure this is float32
arr = arr.astype(np.float32)
with rasterio.open(output, 'w', **profile) as dst:
dst.write(arr)