# Copyright (c) 2017-2025 Satpy developers
#
# This file is part of satpy.
#
# satpy is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# satpy. If not, see <http://www.gnu.org/licenses/>.
"""Enhancements based on convolution."""
from __future__ import annotations
import logging
import dask.array as da
import numpy as np
from .wrappers import exclude_alpha, on_dask_array, on_separate_bands
LOG = logging.getLogger(__name__)
[docs]
def three_d_effect(img, **kwargs):
"""Create 3D effect using convolution."""
w = kwargs.get("weight", 1)
LOG.debug("Applying 3D effect with weight %.2f", w)
kernel = np.array([[-w, 0, w],
[-w, 1, w],
[-w, 0, w]])
mode = kwargs.get("convolve_mode", "same")
return _three_d_effect(img.data, kernel=kernel, mode=mode)
[docs]
@exclude_alpha
@on_separate_bands
@on_dask_array
def _three_d_effect(band_data, kernel=None, mode=None, index=None):
del index
new_data = da.map_blocks(
_three_d_effect_numpy,
band_data.rechunk(band_data.shape),
kernel,
mode,
dtype=band_data.dtype,
meta=np.ndarray((), dtype=band_data.dtype),
)
return new_data.rechunk(band_data.chunks)
[docs]
def _three_d_effect_numpy(band_data, kernel, mode):
"""Kernel for running delayed 3D effect creation."""
from scipy.signal import convolve2d
band_data = band_data.reshape(band_data.shape[1:])
new_data = convolve2d(band_data, kernel, mode=mode)
return new_data.reshape((1, band_data.shape[0], band_data.shape[1]))