tensorflow 1.0 学习：用CNN进行图像分类
tensorflow升级到1.0之后，增加了一些高级模块： 如tf.layers, tf.metrics, 和tf.losses，使得代码稍微有些简化。
任务：花卉分类
版本：tensorflow 1.0
数据：http://download.tensorflow.org/example_images/flower_photos.tgz
花总共有五类，分别放在5个文件夹下。
闲话不多说，直接上代码，希望大家能看懂：）
# -*- coding: utf-8 -*- from skimage import io,transform import glob import os import tensorflow as tf import numpy as np import time path='e:/flower/' #将所有的图片resize成100*100 w=100 h=100 c=3 #读取图片 def read_img(path): cate=[path+x for x in os.listdir(path) if os.path.isdir(path+x)] imgs=[] labels=[] for idx,folder in enumerate(cate): for im in glob.glob(folder+'/*.jpg'): print('reading the images:%s'%(im)) img=io.imread(im) img=transform.resize(img,(w,h)) imgs.append(img) labels.append(idx) return np.asarray(imgs,np.float32),np.asarray(labels,np.int32) data,label=read_img(path) #打乱顺序 num_example=data.shape[0] arr=np.arange(num_example) np.random.shuffle(arr) data=data[arr] label=label[arr] #将所有数据分为训练集和验证集 ratio=0.8 s=np.int(num_example*ratio) x_train=data[:s] y_train=label[:s] x_val=data[s:] y_val=label[s:] #-----------------构建网络---------------------- #占位符 x=tf.placeholder(tf.float32,shape=[None,w,h,c],name='x') y_=tf.placeholder(tf.int32,shape=[None,],name='y_') #第一个卷积层（100——>50) conv1=tf.layers.conv2d( inputs=x, filters=32, kernel_size=[5, 5], padding="same", activation=tf.nn.relu, kernel_initializer=tf.truncated_normal_initializer(stddev=0.01)) pool1=tf.layers.max_pooling2d(inputs=conv1, pool_size=[2, 2], strides=2) #第二个卷积层(50->25) conv2=tf.layers.conv2d( inputs=pool1, filters=64, kernel_size=[5, 5], padding="same", activation=tf.nn.relu, kernel_initializer=tf.truncated_normal_initializer(stddev=0.01)) pool2=tf.layers.max_pooling2d(inputs=conv2, pool_size=[2, 2], strides=2) #第三个卷积层(25->12) conv3=tf.layers.conv2d( inputs=pool2, filters=128, kernel_size=[3, 3], padding="same", activation=tf.nn.relu, kernel_initializer=tf.truncated_normal_initializer(stddev=0.01)) pool3=tf.layers.max_pooling2d(inputs=conv3, pool_size=[2, 2], strides=2) #第四个卷积层(12->6) conv4=tf.layers.conv2d( inputs=pool3, filters=128, kernel_size=[3, 3], padding="same", activation=tf.nn.relu, kernel_initializer=tf.truncated_normal_initializer(stddev=0.01)) pool4=tf.layers.max_pooling2d(inputs=conv4, pool_size=[2, 2], strides=2) re1 = tf.reshape(pool4, [-1, 6 * 6 * 128]) #全连接层 dense1 = tf.layers.dense(inputs=re1, units=1024, activation=tf.nn.relu, kernel_initializer=tf.truncated_normal_initializer(stddev=0.01), kernel_regularizer=tf.contrib.layers.l2_regularizer(0.003)) dense2= tf.layers.dense(inputs=dense1, units=512, activation=tf.nn.relu, kernel_initializer=tf.truncated_normal_initializer(stddev=0.01), kernel_regularizer=tf.contrib.layers.l2_regularizer(0.003)) logits= tf.layers.dense(inputs=dense2, units=5, activation=None, kernel_initializer=tf.truncated_normal_initializer(stddev=0.01), kernel_regularizer=tf.contrib.layers.l2_regularizer(0.003)) #---------------------------网络结束--------------------------- loss=tf.losses.sparse_softmax_cross_entropy(labels=y_,logits=logits) train_op=tf.train.AdamOptimizer(learning_rate=0.001).minimize(loss) correct_prediction = tf.equal(tf.cast(tf.argmax(logits,1),tf.int32), y_) acc= tf.reduce_mean(tf.cast(correct_prediction, tf.float32)) #定义一个函数，按批次取数据 def minibatches(inputs=None, targets=None, batch_size=None, shuffle=False): assert len(inputs) == len(targets) if shuffle: indices = np.arange(len(inputs)) np.random.shuffle(indices) for start_idx in range(0, len(inputs) - batch_size + 1, batch_size): if shuffle: excerpt = indices[start_idx:start_idx + batch_size] else: excerpt = slice(start_idx, start_idx + batch_size) yield inputs[excerpt], targets[excerpt] #训练和测试数据，可将n_epoch设置更大一些 n_epoch=10 batch_size=64 sess=tf.InteractiveSession() sess.run(tf.global_variables_initializer()) for epoch in range(n_epoch): start_time = time.time() #training train_loss, train_acc, n_batch = 0, 0, 0 for x_train_a, y_train_a in minibatches(x_train, y_train, batch_size, shuffle=True): _,err,ac=sess.run([train_op,loss,acc], feed_dict={x: x_train_a, y_: y_train_a}) train_loss += err; train_acc += ac; n_batch += 1 print(" train loss: %f" % (train_loss/ n_batch)) print(" train acc: %f" % (train_acc/ n_batch)) #validation val_loss, val_acc, n_batch = 0, 0, 0 for x_val_a, y_val_a in minibatches(x_val, y_val, batch_size, shuffle=False): err, ac = sess.run([loss,acc], feed_dict={x: x_val_a, y_: y_val_a}) val_loss += err; val_acc += ac; n_batch += 1 print(" validation loss: %f" % (val_loss/ n_batch)) print(" validation acc: %f" % (val_acc/ n_batch)) sess.close()
