def pixel(x, y, width_x, width_y):
    """Spatial representation of a pixel.

    Parameters
    ----------
    x : numpy.ndarray
        x coordinates
    y : numpy.ndarray
        y coordinates
    width_x : float
        x diameter of the pixel, in microns
    width_y : float
        y diameter of the pixel, in microns

    Returns
    -------
    numpy.ndarray
        spatial representation of the pixel

    """
    width_x = width_x / 2
    width_y = width_y / 2
    return (x <= width_x) & (x >= -width_x) & (y <= width_y) & (y >= -width_y)