python生成tensorflow输入输出的图像格式的方法

yipeiwu_com5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

python中的subprocess.Popen()使用详解

从python2.4版本开始,可以用subprocess这个模块来产生子进程,并连接到子进程的标准输入/输出/错误中去,还可以得到子进程的返回值。 subprocess意在替代其他几个老...

Python实现网站注册验证码生成类

本文实例为大家分享了Python网站注册验证码生成类的具体代码,供大家参考,具体内容如下 # -*- coding:utf-8 -*- ''' Created on 2017年4月7...

Python的Asyncore异步Socket模块及实现端口转发的例子

Asyncore模块提供了以异步的方式写入套接字服务客户端和服务器的基础结构。 只有两种方式使一个程序在单处理器上实现“同时做不止一件事”。多线程编程是最简单和最流行的方式,但是有另一种...

python+selenium实现自动化百度搜索关键词

python+selenium实现自动化百度搜索关键词

通过python配合爬虫接口利用selenium实现自动化打开chrome浏览器,进行百度关键词搜索。 1、安装python3,访问官网选择对应的版本安装即可,最新版为3.7。 2、安...

Python socket 套接字实现通信详解

首先:我们介绍一下socket什么是socket: 1. socket 在操作系统中它是处于应用层与传输层的抽象层,它是一组操作起来非常简单的接口(接收数据的),此接口接受数据之后交个...