'Computes the center coordinates, height and width of the boxes.
Args:
scope: name scope of the function.
Returns:
a list of 4 1-D tensors [ycenter, xcenter, height, width].'

def get_center_coordinates_and_sizes(self, scope=None):

    with tf.name_scope(scope, 'get_center_coordinates_and_sizes'):
        box_corners = self.get()
        (ymin, xmin, ymax, xmax) = tf.unstack(tf.transpose(box_corners))
        width = (xmax - xmin)
        height = (ymax - ymin)
        ycenter = (ymin + (height / 2.0))
        xcenter = (xmin + (width / 2.0))
        return [ycenter, xcenter, height, width]
