Tensorflow内存呈指数增长

Question

此代码段中我面临内存不足的问题。

import tensorflow as tf
from architecture import inception_resnet_v1 as resnet
from tensorflow.python.platform import gfile
import numpy as np
import os
class FaceFeature(object):
    def __init__(self, face_rec_graph, model_path = 'models/20170512-110547.pb'):
        '''

        :param face_rec_sess: FaceRecSession object
        :param model_path:
        '''
        print("Loading model...")
        with face_rec_graph.graph.as_default():
            self.sess = tf.Session()
            with self.sess.as_default():
                self.__load_model(model_path)
                self.x = tf.get_default_graph() \
                                            .get_tensor_by_name("input:0")
                self.embeddings = tf.get_default_graph() \
                                    .get_tensor_by_name("embeddings:0")
                self.phase_train_placeholder = tf.get_default_graph() \
                                                     .get_tensor_by_name("phase_train:0")                    

                print("Model loaded")


    def get_features(self, input_imgs):
        images = load_data_list(input_imgs,160)
        feed_dict = {self.x: images, self.phase_train_placeholder: False}

        return self.sess.run(self.embeddings, feed_dict = feed_dict)



    def __load_model(self, model):
        # Check if the model is a model directory (containing a metagraph and a checkpoint file)
        #  or if it is a protobuf file with a frozen graph
        model_exp = os.path.expanduser(model)
        if os.path.isfile(model_exp):
            print('Model filename: %s' % model_exp)
            with gfile.FastGFile(model_exp, 'rb') as file_:
                graph_def = tf.GraphDef()
                graph_def.ParseFromString(file_.read())
                tf.import_graph_def(graph_def, name='')
        else:
            print('Model directory: %s' % model_exp)
            meta_file, ckpt_file = get_model_filenames(model_exp)
            print('Metagraph file: %s' % meta_file)
            print('Checkpoint file: %s' % ckpt_file)
            saver = tf.train.import_meta_graph(os.path.join(model_exp, meta_file))
            saver.restore(tf.get_default_session(), os.path.join(model_exp, ckpt_file))


def get_model_filenames(model_dir):
    files = os.listdir(model_dir)
    meta_files = [s for s in files if s.endswith('.meta')]
    if len(meta_files) == 0:
        raise ValueError('No meta file found in the model directory (%s)' % model_dir)
    elif len(meta_files) > 1:
        raise ValueError('There should not be more than one meta file \
                                    in the model directory (%s)' % model_dir)
    meta_file = meta_files[0]
    meta_files = [s for s in files if '.ckpt' in s]
    max_step = -1
    for file_ in files:
        step_str = re.match(r'(^model-[\w\- ]+.ckpt-(\d+))', file_)
        if step_str is not None and len(step_str.groups()) >= 2:
            step = int(step_str.groups()[1])
            if step > max_step:
                max_step = step
                ckpt_file = step_str.groups()[0]
    return meta_file, ckpt_file

def tensorization(img):
    '''
    Prepare the imgs before input into model
    :param img: Single face image
    :return tensor: numpy array in shape(n, 160, 160, 3) ready for input to cnn
    '''
    tensor = img.reshape(-1, Config.Align.IMAGE_SIZE, Config.Align.IMAGE_SIZE, 3)
    return tensor

#some image preprocess stuff
def prewhiten(x):
    mean = np.mean(x)
    std = np.std(x)
    std_adj = np.maximum(std, 1.0 / np.sqrt(x.size))
    y = np.multiply(np.subtract(x, mean), 1 / std_adj)
    return y

def load_data_list(imgList, image_size, do_prewhiten=True):
    images = np.zeros((len(imgList), image_size, image_size, 3))
    i = 0
    for img in imgList:
        if img is not None:
            if do_prewhiten:
                img = prewhiten(img)
            images[i, :, :, :] = img
            i += 1
    return images



terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc
Aborted

调用 get_features（）时，内存一直以指数级增长，并且没有释放。如果有人能帮助我，那就太好了。

以上用于面部特征提取以进行面部识别。该代码位于https://github.com/vudung45/FaceRec/blob/master/face_feature.py