tensorflow_juanji.py

#!/usr/bin/python
#coding=utf-8
''' juanji convolution nn'''
# pylint: disable=invalid-name

import os
import logging as log
import matplotlib.pyplot as plt
import common
from tensorflow.examples.tutorials.mnist import input_data
import tensorflow as tf

def deepnn(x):
    """deepnn builds the graph for a deep net for classifying digits.
    Args:
        x: an input tensor with the dimensions (N_examples, 784), where 784 is the
        number of pixels in a standard MNIST image.
    Returns:
        A tuple (y, keep_prob). y is a tensor of shape (N_examples, 10), with values
        equal to the logits of classifying the digit into one of 10 classes (the
        digits 0-9). keep_prob is a scalar placeholder for the probability of
        dropout.
    """
    # Reshape to use within a convolutional neural net.
    # Last dimension is for "features" - there is only one here, since images are
    # grayscale -- it would be 3 for an RGB image, 4 for RGBA, etc.
    with tf.name_scope('reshape'):
        x_image = tf.reshape(x, [-1, 28, 28, 1])

    # First convolutional layer - maps one grayscale image to 32 feature maps.
    with tf.name_scope('conv1'):
        W_conv1 = weight_variable([5, 5, 1, 32])
        b_conv1 = bias_variable([32])
        h_conv1 = tf.nn.relu(conv2d(x_image, W_conv1) + b_conv1)

    # Pooling layer - downsamples by 2X.
    with tf.name_scope('pool1'):
        h_pool1 = max_pool_2x2(h_conv1)

    # Second convolutional layer -- maps 32 feature maps to 64.
    with tf.name_scope('conv2'):
        W_conv2 = weight_variable([5, 5, 32, 64])
        b_conv2 = bias_variable([64])
        h_conv2 = tf.nn.relu(conv2d(h_pool1, W_conv2) + b_conv2)

    # Second pooling layer.
    with tf.name_scope('pool2'):
        h_pool2 = max_pool_2x2(h_conv2)

    # Fully connected layer 1 -- after 2 round of downsampling, our 28x28 image
    # is down to 7x7x64 feature maps -- maps this to 1024 features.
    with tf.name_scope('fc1'):
        W_fc1 = weight_variable([7 * 7 * 64, 1024])
        b_fc1 = bias_variable([1024])

        h_pool2_flat = tf.reshape(h_pool2, [-1, 7*7*64])
        h_fc1 = tf.nn.relu(tf.matmul(h_pool2_flat, W_fc1) + b_fc1)

    # Dropout - controls the complexity of the model, prevents co-adaptation of
    # features.
    with tf.name_scope('dropout'):
        keep_prob = tf.placeholder(tf.float32)
        h_fc1_drop = tf.nn.dropout(h_fc1, keep_prob)

    # Map the 1024 features to 10 classes, one for each digit
    with tf.name_scope('fc2'):
        W_fc2 = weight_variable([1024, 10])
        b_fc2 = bias_variable([10])

        y_conv = tf.matmul(h_fc1_drop, W_fc2) + b_fc2
    return y_conv, keep_prob


def conv2d(x, W):
    """conv2d returns a 2d convolution layer with full stride."""
    return tf.nn.conv2d(x, W, strides=[1, 1, 1, 1], padding='SAME')


def max_pool_2x2(x):
    """max_pool_2x2 downsamples a feature map by 2X."""
    return tf.nn.max_pool(x, ksize=[1, 2, 2, 1],
                          strides=[1, 2, 2, 1], padding='SAME')


def weight_variable(shape):
    """weight_variable generates a weight variable of a given shape."""
    initial = tf.truncated_normal(shape, stddev=0.1)
    return tf.Variable(initial)


def bias_variable(shape):
    """bias_variable generates a bias variable of a given shape."""
    initial = tf.constant(0.1, shape=shape)
    return tf.Variable(initial)

def main(_):
    ''' main'''
    # Import data
    mnist = input_data.read_data_sets('./', one_hot=True)

    # Create the model
    x = tf.placeholder(tf.float32, [None, 784])

    # Define loss and optimizer
    y_ = tf.placeholder(tf.float32, [None, 10])

    # Build the graph for the deep net
    y_conv, keep_prob = deepnn(x)

    with tf.name_scope('loss'):
        cross_entropy = tf.nn.softmax_cross_entropy_with_logits(labels=y_,
                                                                logits=y_conv)
    cross_entropy = tf.reduce_mean(cross_entropy)

    with tf.name_scope('adam_optimizer'):
        train_step = tf.train.AdamOptimizer(1e-4).minimize(cross_entropy)

    with tf.name_scope('accuracy'):
        correct_prediction = tf.equal(tf.argmax(y_conv, 1), tf.argmax(y_, 1))
        correct_prediction = tf.cast(correct_prediction, tf.float32)
    accuracy = tf.reduce_mean(correct_prediction)

    '''graph_location = tempfile.mkdtemp()
    print('Saving graph to: %s' % graph_location)
    train_writer = tf.summary.FileWriter(graph_location)
    train_writer.add_graph(tf.get_default_graph())'''

    savepath = './checkpoint/juanji.ckpt'
    istraining = 0
    if os.path.exists(savepath+'.meta') is not True:
        istraining = 1

    saver = tf.train.Saver()
    if istraining == 1:
        with tf.Session() as sess:
            sess.run(tf.global_variables_initializer())
            for i in range(2000):
                batch = mnist.train.next_batch(50)
                if i % 100 == 0:
                    train_accuracy = accuracy.eval(feed_dict={
                        x: batch[0], y_: batch[1], keep_prob: 1.0})
                    log.debug('step %d, training accuracy %g', i, train_accuracy)
                train_step.run(feed_dict={x: batch[0], y_: batch[1], keep_prob: 0.5})

            batch = mnist.test.next_batch(2000)
            log.debug('test accuracy %g',
                      accuracy.eval(feed_dict={x: batch[0], y_: batch[1], keep_prob: 1.0}))
            saver.save(sess, savepath)

    with tf.Session() as sess:
        sess.run(tf.global_variables_initializer())
        saver.restore(sess, savepath)
        #myimg = common.getimgdata('./mydrawnum3.bmp')
        myimg = common.getimgdata('./image/number3.png')
        ndimg = myimg.reshape(1, 28 * 28)
        log.debug(sess.run([y_conv, tf.argmax(y_conv, 1)],
                           feed_dict={x: ndimg, keep_prob: 1.0}))
        plt.imshow(myimg)
        common.blockplt()

if __name__ == '__main__':
    main(0)