def execute(mp):
"""Enhance RGB colors from a Sentinel-2 SAFE archive."""
# read input SAFE file
with mp.open(
"input_file", resampling=mp.params["resampling"]
) as safe_file:
try:
# read red, green and blue bands & scale to 8 bit
rgb = np.clip(
safe_file.read(
[4, 3, 2],
mask_clouds=mp.params["mask_clouds"],
mask_white_areas=mp.params["mask_white_areas"]
) / 16, 0, 255
).astype("uint8")
except MapcheteEmptyInputTile:
return "empty"
# scale to 0 to 1 for filters
red, green, blue = rgb.astype("float") / 255
# save nodata mask for later & remove rgb to free memory
mask = rgb.mask
del rgb
# using rio-color:
# (1) apply gamma correction to each band individually
# (2) add sigmoidal contrast & bias
# (3) add saturation
enhanced = np.clip(
saturation(
sigmoidal(
np.stack([
# apply gamma correction for each band
gamma(red, mp.params["red_gamma"]),
gamma(green, mp.params["green_gamma"]),
gamma(blue, mp.params["blue_gamma"]),
]),
mp.params["sigmoidal_contrast"],
mp.params["sigmoidal_bias"]
),
mp.params["saturation"]
) * 255, # scale back to 8bit
1, 255 # clip valid values from 1 to 255
)
# use original nodata mask and return
return np.where(mask, 0, enhanced).astype("uint8")
def test_sat_rgba_direct(arr_rgba):
# Anything but 3-band RGB will fail
with pytest.raises(ValueError):
saturation(arr_rgba, 50)
with pytest.raises(ValueError):
saturation(arr_rgba[0:2], 50)
def test_sat(arr):
x = saturation(arr, 50)
assert x[0][0][0] - 0.15860622 < 1e-4
def test_parse_multi_saturation_first(arr):
f1, f2 = parse_operations("saturation 1.25 gamma rgb 0.95")
assert np.array_equal(f2(f1(arr)), gamma(saturation(arr, 1.25), g=0.95))
def test_parse_saturation_rgb(arr):
f = parse_operations("saturation 1.25")[0]
assert np.allclose(f(arr), saturation(arr, 1.25))
