def pixel_coordinate(origin_x, scale_x, theta_y, origin_y, theta_x, scale_y, i, j):
    """
    Returns the Cartesian coordinate for a pixel

    http://www.gdal.org/gdal_datamodel.html

    Args:
        origin_x (float): the X dimension of the spatial coordinate for the top
            left pixel
        scale_x (float): the spatial width of pixels in the X dimension
        theta_y (float): the spatial offset in the Y dimension caused by
            rotation
        origin_y (float): the Y dimension of the spatial coordinate for the top
            left pixel
        theta_x (float): the spatial offset in the X dimension caused by
            rotation
        scale_y (float): the spatial height of pixels in the Y dimension
        i (int): the X dimension grid index for the desired pixel
        j (int): the Y dimension grid index for the desired pixel

    Returns:
        coord (tuple): the Cartesian coordinate for the pixel in (x, y) form
    """

    x_coordinate = origin_x + (i * scale_x) + (j * theta_y)
    y_coordinate = origin_y + (i * theta_x) + (j * scale_y)

    return (x_coordinate, y_coordinate)