preprocessing.py 文件源码

def compute_binary_mask_sprengel(spectrogram, threshold):
    """ Computes a binary mask for the spectrogram
    # Arguments
        spectrogram : a numpy array representation of a spectrogram (2-dim)
        threshold   : a threshold for times larger than the median
    # Returns
        binary_mask : the binary mask
    """
    # normalize to [0, 1)
    norm_spectrogram = normalize(spectrogram)

    # median clipping
    binary_image = median_clipping(norm_spectrogram, threshold)

    # erosion
    binary_image = morphology.binary_erosion(binary_image, selem=np.ones((4, 4)))

    # dilation
    binary_image = morphology.binary_dilation(binary_image, selem=np.ones((4, 4)))

    # extract mask
    mask = np.array([np.max(col) for col in binary_image.T])
    mask = smooth_mask(mask)

    return mask