def _get_quantification_value(metadata):
    """Gets the quantification value (to compute correct reflectances)"""
    if metadata['PROCESSING_LEVEL'] == 'Level-1C':
        quantification_value = float(metadata['QUANTIFICATION_VALUE'])
    else:   # L2A
        quantification_value = float(metadata['BOA_QUANTIFICATION_VALUE'])
    return quantification_value