# Copyright 2021 Shivam Pandey
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import numpy as np
from scipy.ndimage import gaussian_filter


def gaussian(mat, mask, sigma=2):
    """
    Applies the Gaussian filtering to the system
    :param mat: image/data
    :param mask:
    :param sigma: float standard deviation
    :return:
    """
    filtered_mat = gaussian_filter(mat, sigma, mode='constant')
    filtered_mat[mask] = np.nan
    return filtered_mat
