def blk_coverage_1d(blk, size):
    """Return the part of a 1d array covered by a block.

    :param blk: size of the 1d block
    :param size: size of the 1d a image
    :return: a tuple of size covered and remaining size

    Example:

        >>> blk_coverage_1d(7, 100)
        (98, 2)

    """
    rem = size % blk
    maxpix = size - rem
    return maxpix, rem