我是TensorFlow和机器学习的新手(也是python)。 在创建图像识别程序的第一步,我在喂食数据准备时遇到了困惑。有人可以帮我这个吗? 我查看了本教程,但数据准备工作是混淆的。 mnis softmax for beginner
我没想到从这个问题中得到一个完整的完美程序,相反我很想听听你是否可以告诉我TensorFlow如何在feed_dict上工作。现在在我看来,它是:“工作就像一个[for]循环,通过imageHolder,得到2352字节/ 1图像的数据并放入训练操作,在那里它执行基于当前模型的预测并与之比较来自同一指数的labelHolder的数据然后对模型进行修正。“所以我期望放入一组2352字节的数据(另一个相同大小的图像)并得到预测。我也会把代码放在这里,以防我的想法是正确的,错误来自糟糕的实现。
说:我有5个班级的掀起数据,总共有3670个图像。 将数据加载到feed_dict进行训练时,我已将所有图像转换为28x28像素,包含3个通道。它导致feed_dict中图像持有者的张量为(3670,2352)。之后,我设法在feed_dict中为标签持有者准备了一个(3670,)的张量。 培训代码如下所示:
for step in xrange(FLAGS.max_steps):
feed_dict = {
imageHolder: imageTrain,
labelHolder: labelTrain,
}
_, loss_rate = sess.run([train_op, loss_op], feed_dict=feed_dict)
然后我的代码用上面的模型预测新图像:
testing_dataset = do_get_file_list(FLAGS.guess_dir)
x = tf.placeholder(tf.float32, shape=(IMAGE_PIXELS))
for data in testing_dataset:
image = Image.open(data)
image = image.resize((IMAGE_SIZE, IMAGE_SIZE))
image = np.array(image).reshape(IMAGE_PIXELS)
prediction = session.run(tf.argmax(logits, 1), feed_dict={x: image})
但问题是,无论我的测试数据是什么形状(2352,),(1,2352),预测线总是会引发“无法提供形状值......”的错误(它要求( 3670,2352)形状,但没办法)
这是我用过的一些旗帜
IMAGE_SIZE = 28
CHANNELS = 3
IMAGE_PIXELS = IMAGE_SIZE * IMAGE_SIZE * CHANNELS
培训操作和损失计算:
def do_get_op_compute_loss(logits, labels):
labels = tf.to_int64(labels)
cross_entropy = tf.nn.sparse_softmax_cross_entropy_with_logits(labels=labels, logits=logits, name='xentropy')
loss = tf.reduce_mean(cross_entropy, name='xentropy_mean')
return loss
def do_get_op_training(loss_op, training_rate):
optimizer = tf.train.GradientDescentOptimizer(FLAGS.learning_rate)
global_step = tf.Variable(0, name='global_step', trainable=False)
train_op = optimizer.minimize(loss_op, global_step=global_step)
return train_op
变量
imageHolder = tf.placeholder(tf.float32, [data_count, IMAGE_PIXELS])
labelHolder = tf.placeholder(tf.int32, [data_count])
完整的程序:
import os
import math
import tensorflow as tf
from PIL import Image
import numpy as np
from six.moves import xrange
flags = tf.app.flags
FLAGS = flags.FLAGS
flags.DEFINE_float('learning_rate', 0.01, 'Initial learning rate.')
flags.DEFINE_integer('max_steps', 200, 'Number of steps to run trainer.')
flags.DEFINE_integer('hidden1', 128, 'Number of units in hidden layer 1.')
flags.DEFINE_integer('hidden2', 32, 'Number of units in hidden layer 2.')
flags.DEFINE_integer('batch_size', 4, 'Batch size. '
'Must divide evenly into the dataset sizes.')
flags.DEFINE_string('train_dir', 'data', 'Directory to put the training data.')
flags.DEFINE_string('save_file', '.\\data\\model.ckpt', 'Directory to put the training data.')
flags.DEFINE_string('guess_dir', 'work', 'Directory to put the testing data.')
#flags.DEFINE_boolean('fake_data', False, 'If true, uses fake data '
# 'for unit testing.')
IMAGE_SIZE = 28
CHANNELS = 3
IMAGE_PIXELS = IMAGE_SIZE * IMAGE_SIZE * CHANNELS
def do_inference(images, hidden1_units, hidden2_units, class_count):
#HIDDEN LAYER 1
with tf.name_scope('hidden1'):
weights = tf.Variable(
tf.truncated_normal([IMAGE_PIXELS, hidden1_units], stddev=1.0 / math.sqrt(float(IMAGE_PIXELS))),
name='weights')
biases = tf.Variable(tf.zeros([hidden1_units]), name='biases')
hidden1 = tf.nn.relu(tf.matmul(images, weights) + biases)
#HIDDEN LAYER 2
with tf.name_scope('hidden1'):
weights = tf.Variable(
tf.truncated_normal([hidden1_units, hidden2_units], stddev=1.0 / math.sqrt(float(hidden1_units))),
name='weights')
biases = tf.Variable(tf.zeros([hidden2_units]), name='biases')
hidden2 = tf.nn.relu(tf.matmul(hidden1, weights) + biases)
#LINEAR
with tf.name_scope('softmax_linear'):
weights = tf.Variable(
tf.truncated_normal([hidden2_units, class_count], stddev=1.0 / math.sqrt(float(hidden2_units))),
name='weights')
biases = tf.Variable(tf.zeros([class_count]), name='biases')
logits = tf.matmul(hidden2, weights) + biases
return logits
def do_get_op_compute_loss(logits, labels):
labels = tf.to_int64(labels)
cross_entropy = tf.nn.sparse_softmax_cross_entropy_with_logits(labels=labels, logits=logits, name='xentropy')
loss = tf.reduce_mean(cross_entropy, name='xentropy_mean')
return loss
def do_get_op_training(loss_op, training_rate):
optimizer = tf.train.GradientDescentOptimizer(FLAGS.learning_rate)
global_step = tf.Variable(0, name='global_step', trainable=False)
train_op = optimizer.minimize(loss_op, global_step=global_step)
return train_op
def do_get_op_evaluate(logits, labels):
correct = tf.nn.in_top_k(logits, labels, 1)
return tf.reduce_sum(tf.cast(correct, tf.int32))
def do_evaluate(session, eval_correct_op, imageset_holder, labelset_holder, train_images, train_labels):
true_count = 0
num_examples = FLAGS.batch_size * FLAGS.batch_size
for step in xrange(FLAGS.batch_size):
feed_dict = {imageset_holder: train_images, labelset_holder: train_labels,}
true_count += session.run(eval_correct_op, feed_dict=feed_dict)
precision = true_count / num_examples
# print(' Num examples: %d Num correct: %d Precision @ 1: %0.04f' %
# (num_examples, true_count, precision))
def do_init_param(data_count, class_count):
# Generate placeholder
imageHolder = tf.placeholder(tf.float32, shape=(data_count, IMAGE_PIXELS))
labelHolder = tf.placeholder(tf.int32, shape=(data_count))
# Build a graph for prediction from inference model
logits = do_inference(imageHolder, FLAGS.hidden1, FLAGS.hidden2, class_count)
# Add loss calculating op
loss_op = do_get_op_compute_loss(logits, labelHolder)
# Add training op
train_op = do_get_op_training(loss_op, FLAGS.learning_rate)
# Add evaluate correction op
evaluate_op = do_get_op_evaluate(logits, labelHolder)
# Create session for op operating
sess = tf.Session()
# Init param
init = tf.initialize_all_variables()
sess.run(init)
return sess, train_op, loss_op, evaluate_op, imageHolder, labelHolder, logits
def do_get_class_list():
return [{'name': name, 'path': os.path.join(FLAGS.train_dir, name)} for name in os.listdir(FLAGS.train_dir)
if os.path.isdir(os.path.join(FLAGS.train_dir, name))]
def do_get_file_list(folderName):
return [os.path.join(folderName, name) for name in os.listdir(folderName)
if (os.path.isdir(os.path.join(folderName, name)) == False)]
def do_init_data_list():
file_list = []
for classItem in do_get_class_list():
for dataItem in do_get_file_list(classItem['path']):
file_list.append({'name': classItem['name'], 'path': dataItem})
# Renew data feeding dictionary
imageTrainList, labelTrainList = do_seperate_data(file_list)
imageTrain = []
for imagePath in imageTrainList:
image = Image.open(imagePath)
image = image.resize((IMAGE_SIZE, IMAGE_SIZE))
imageTrain.append(np.array(image))
imageCount = len(imageTrain)
imageTrain = np.array(imageTrain)
imageTrain = imageTrain.reshape(imageCount, IMAGE_PIXELS)
id_list, id_map = do_generate_id_label(labelTrainList)
labelTrain = np.array(id_list)
return imageTrain, labelTrain, id_map
def do_init():
imageTrain, labelTrain, id_map = do_init_data_list()
sess, train_op, loss_op, evaluate_op, imageHolder, labelHolder, logits = do_init_param(len(imageTrain), len(id_map))
return sess, train_op, loss_op, evaluate_op, imageHolder, labelHolder, imageTrain, labelTrain, id_map, logits
def do_seperate_data(data):
images = [item['path'] for item in data]
labels = [item['name'] for item in data]
return images, labels
def do_generate_id_label(label_list):
trimmed_label_list = list(set(label_list))
id_map = {trimmed_label_list.index(label): label for label in trimmed_label_list}
reversed_id_map = {label: trimmed_label_list.index(label) for label in trimmed_label_list}
id_list = [reversed_id_map.get(item) for item in label_list]
return id_list, id_map
def do_training(sess, train_op, loss_op, evaluate_op, imageHolder, labelHolder, imageTrain, labelTrain):
# Training state checkpoint saver
saver = tf.train.Saver()
# feed_dict = {
# imageHolder: imageTrain,
# labelHolder: labelTrain,
# }
for step in xrange(FLAGS.max_steps):
feed_dict = {
imageHolder: imageTrain,
labelHolder: labelTrain,
}
_, loss_rate = sess.run([train_op, loss_op], feed_dict=feed_dict)
if step % 100 == 0:
print('Step {0}: loss = {1}'.format(step, loss_rate))
if (step + 1) % 1000 == 0 or (step + 1) == FLAGS.max_steps:
saver.save(sess, FLAGS.save_file, global_step=step)
print('Evaluate training data')
do_evaluate(sess, evaluate_op, imageHolder, labelHolder, imageTrain, labelTrain)
def do_predict(session, logits):
# xentropy
testing_dataset = do_get_file_list(FLAGS.guess_dir)
x = tf.placeholder(tf.float32, shape=(IMAGE_PIXELS))
print('Perform predict')
print('==================================================================================')
# TEMPORARY CODE
for data in testing_dataset:
image = Image.open(data)
image = image.resize((IMAGE_SIZE, IMAGE_SIZE))
image = np.array(image).reshape(IMAGE_PIXELS)
print(image.shape)
prediction = session.run(logits, {x: image})
print('{0}: {1}'.format(data, prediction))
def main(_):
# TF notice default graph
with tf.Graph().as_default():
sess, train_op, loss_op, evaluate_op, imageHolder, labelHolder, imageTrain, labelTrain, id_map, logits = do_init()
print("done init")
do_training(sess, train_op, loss_op, evaluate_op, imageHolder, labelHolder, imageTrain, labelTrain)
print("done training")
do_predict(sess, logits)
# NO IDEA
if __name__ == '__main__':
tf.app.run()
答案 0 :(得分:0)
理解错误很重要,你说
但问题是预测线总是引发错误“不能 塑料的形状......“无论我的测试数据是什么形状 (2352,),(1,2352)(它要求(3670,2352)形状,但没办法)
哦,是的,我的朋友,是的。它说你的形状有问题,你需要检查一下。它要求3670,为什么?
因为您的模型接受带有形状的输入(data_count,IMAGE_PIXELS),您在下面声明:
def do_init_param(data_count, class_count):
# Generate placeholder
imageHolder = tf.placeholder(tf.float32, shape=(data_count, IMAGE_PIXELS))
labelHolder = tf.placeholder(tf.int32, shape=(data_count))
此函数在此处调用:
sess, train_op, loss_op, evaluate_op, imageHolder, labelHolder, logits = do_init_param(len(imageTrain), len(id_map))
len(imageTrain)
是数据集的长度,可能是3670张图片。
然后你有预测功能:
def do_predict(session, logits):
# xentropy
testing_dataset = do_get_file_list(FLAGS.guess_dir)
x = tf.placeholder(tf.float32, shape=(IMAGE_PIXELS))
...
prediction = session.run(logits, {x: image})
注意x
这里没用。你正在喂你的图像以预测你的模型不期望这种形状,它期望原始的占位符形状(3670,2352),因为这就是你所说的。
解决方案是将x
声明为具有非特定第一维的占位符,例如:
imageHolder = tf.placeholder(tf.float32, shape=(None, IMAGE_PIXELS))
当您预测图像的标签时,您可以拥有单个图像或多个图像(小批量),但始终必须具有形状[number_images,IMAGE_PIXELS]。
有道理吗?