python生成tensorflow输入输出的图像格式的方法

yipeiwu_com6年前Python基础

TensorFLow能够识别的图像文件,可以通过numpy,使用tf.Variable或者tf.placeholder加载进tensorflow;也可以通过自带函数(tf.read)读取,当图像文件过多时,一般使用pipeline通过队列的方法进行读取。下面我们介绍两种生成tensorflow的图像格式的方法,供给tensorflow的graph的输入与输出。

import cv2 
import numpy as np 
import h5py 
 
height = 460 
width = 345 
 
with h5py.File('make3d_dataset_f460.mat','r') as f: 
  images = f['images'][:] 
   
image_num = len(images) 
 
data = np.zeros((image_num, height, width, 3), np.uint8) 
data = images.transpose((0,3,2,1)) 

先生成图像文件的路径:ls *.jpg> list.txt

import cv2 
import numpy as np 
 
image_path = './' 
list_file = 'list.txt' 
height = 48 
width = 48 
 
image_name_list = [] # read image 
with open(image_path + list_file) as fid: 
  image_name_list = [x.strip() for x in fid.readlines()] 
image_num = len(image_name_list) 
 
data = np.zeros((image_num, height, width, 3), np.uint8) 
 
for idx in range(image_num): 
  img = cv2.imread(image_name_list[idx]) 
  img = cv2.resize(img, (height, width)) 
  data[idx, :, :, :] = img 

2 Tensorflow自带函数读取

def get_image(image_path): 
  """Reads the jpg image from image_path. 
  Returns the image as a tf.float32 tensor 
  Args: 
    image_path: tf.string tensor 
  Reuturn: 
    the decoded jpeg image casted to float32 
  """ 
  return tf.image.convert_image_dtype( 
    tf.image.decode_jpeg( 
      tf.read_file(image_path), channels=3), 
    dtype=tf.uint8) 

pipeline读取方法

# Example on how to use the tensorflow input pipelines. The explanation can be found here ischlag.github.io. 
import tensorflow as tf 
import random 
from tensorflow.python.framework import ops 
from tensorflow.python.framework import dtypes 
 
dataset_path   = "/path/to/your/dataset/mnist/" 
test_labels_file = "test-labels.csv" 
train_labels_file = "train-labels.csv" 
 
test_set_size = 5 
 
IMAGE_HEIGHT = 28 
IMAGE_WIDTH  = 28 
NUM_CHANNELS = 3 
BATCH_SIZE  = 5 
 
def encode_label(label): 
 return int(label) 
 
def read_label_file(file): 
 f = open(file, "r") 
 filepaths = [] 
 labels = [] 
 for line in f: 
  filepath, label = line.split(",") 
  filepaths.append(filepath) 
  labels.append(encode_label(label)) 
 return filepaths, labels 
 
# reading labels and file path 
train_filepaths, train_labels = read_label_file(dataset_path + train_labels_file) 
test_filepaths, test_labels = read_label_file(dataset_path + test_labels_file) 
 
# transform relative path into full path 
train_filepaths = [ dataset_path + fp for fp in train_filepaths] 
test_filepaths = [ dataset_path + fp for fp in test_filepaths] 
 
# for this example we will create or own test partition 
all_filepaths = train_filepaths + test_filepaths 
all_labels = train_labels + test_labels 
 
all_filepaths = all_filepaths[:20] 
all_labels = all_labels[:20] 
 
# convert string into tensors 
all_images = ops.convert_to_tensor(all_filepaths, dtype=dtypes.string) 
all_labels = ops.convert_to_tensor(all_labels, dtype=dtypes.int32) 
 
# create a partition vector 
partitions = [0] * len(all_filepaths) 
partitions[:test_set_size] = [1] * test_set_size 
random.shuffle(partitions) 
 
# partition our data into a test and train set according to our partition vector 
train_images, test_images = tf.dynamic_partition(all_images, partitions, 2) 
train_labels, test_labels = tf.dynamic_partition(all_labels, partitions, 2) 
 
# create input queues 
train_input_queue = tf.train.slice_input_producer( 
                  [train_images, train_labels], 
                  shuffle=False) 
test_input_queue = tf.train.slice_input_producer( 
                  [test_images, test_labels], 
                  shuffle=False) 
 
# process path and string tensor into an image and a label 
file_content = tf.read_file(train_input_queue[0]) 
train_image = tf.image.decode_jpeg(file_content, channels=NUM_CHANNELS) 
train_label = train_input_queue[1] 
 
file_content = tf.read_file(test_input_queue[0]) 
test_image = tf.image.decode_jpeg(file_content, channels=NUM_CHANNELS) 
test_label = test_input_queue[1] 
 
# define tensor shape 
train_image.set_shape([IMAGE_HEIGHT, IMAGE_WIDTH, NUM_CHANNELS]) 
test_image.set_shape([IMAGE_HEIGHT, IMAGE_WIDTH, NUM_CHANNELS]) 
 
 
# collect batches of images before processing 
train_image_batch, train_label_batch = tf.train.batch( 
                  [train_image, train_label], 
                  batch_size=BATCH_SIZE 
                  #,num_threads=1 
                  ) 
test_image_batch, test_label_batch = tf.train.batch( 
                  [test_image, test_label], 
                  batch_size=BATCH_SIZE 
                  #,num_threads=1 
                  ) 
 
print "input pipeline ready" 
 
with tf.Session() as sess: 
  
 # initialize the variables 
 sess.run(tf.initialize_all_variables()) 
  
 # initialize the queue threads to start to shovel data 
 coord = tf.train.Coordinator() 
 threads = tf.train.start_queue_runners(coord=coord) 
 
 print "from the train set:" 
 for i in range(20): 
  print sess.run(train_label_batch) 
 
 print "from the test set:" 
 for i in range(10): 
  print sess.run(test_label_batch) 
 
 # stop our queue threads and properly close the session 
 coord.request_stop() 
 coord.join(threads) 
 sess.close() 

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持【听图阁-专注于Python设计】。

相关文章

理解Python中的类与实例

面向对象最重要的概念就是类(Class)和实例(Instance),必须牢记类是抽象的模板,比如Student类,而实例是根据类创建出来的一个个具体的“对象”,每个对象都拥有相同的方法,...

python导入模块交叉引用的方法

实际项目中遇到python模块相互引用问题,查资料,终于算是弄明白了。 首先交叉引用或是相互引用,实际上就是导入循环,关于导入循环的详细说明,可见我摘自《python核心编程》第二版的摘...

python实现报表自动化详解

python实现报表自动化详解

本篇文章将介绍: xlwt 常用功能 xlrd 常用功能 xlutils 常用功能 xlwt写Excel时公式的应用 xlwt写入特定目录(路径设置) xlwt Python语言中,写...

Python实战之制作天气查询软件

Python实战之制作天气查询软件

前言 本文主要给大家介绍的是关于Python制作天气查询软件,下面话不多说了,来一起看看详细的介绍吧 效果图 以前,给大家分享了如何使用 PyQt5 制作猜数游戏和计时器,这一次,我们...

python tkinter窗口最大化的实现

最近学习python,刚好学到了gui(tkinter)相关的知识,顺便一提,我学python用的是《programming python 4edition》这本书,在这里小小的推荐一下...