def write_csv(filename, data, delimiter=CSV_DELIMITER):
    """ Write image data to CSV file

    :param filename: name of CSV file to write data to
    :type filename: str
    :param data: image data to write to CSV file
    :type data: numpy array
    :param delimiter: delimiter used in CSV file. Default is ``;``
    :type delimiter: str
    """
    with open(filename, 'w') as file:
        csv_writer = csv.writer(file, delimiter=delimiter)
        for line in data:
            csv_writer.writerow(line)