slim.batch_norm中的moving_mean和moving_variance不是trainable的，所以使用saver = tf.train.Saver(tf.trainable_variables(), max_to_keep=3)無法保存，應該改為：

var_list = tf.trainable_variables()

g_list = tf.global_variables()

bn_moving_vars = [g for g in g_list if 'moving_mean' in g.name]

bn_moving_vars += [g for g in g_list if 'moving_variance' in g.name]

var_list += bn_moving_vars

saver = tf.train.Saver(var_list=var_list, max_to_keep=3)