def _is_pixel(item):
    """
    Returns True if item is a pixel, False otherwise.

    A pixel is a tuple of 3 ints in the range 0..255

    Parameter item: The item to check
    Precondition: NONE (item can be anything)(
    """
    if type(item) != tuple or len(item) != 3:
        return False

    for ii in range(3):
        if type(item[ii]) != int or item[ii] < 0 or item[ii] > 255:
            return False

    return True