cnn 卷积神经网络 人脸识别

  卷积网络博大精深,不同的网络模型,跑出来的结果是不一样,在不知道使用什么网络的情况下跑自己的数据集时,我建议最好去参考基于cnn的手写数字识别网络构建,在其基础上进行改进,对于一般测试数据集有很大的帮助。

分享一个网络构架和一中训练方法:

# coding:utf-8
import os
import tensorflow as tf

os.environ['TF_CPP_MIN_LOG_LEVEL'] = '2'


# cnn模型高度抽象特征
def cnn_face_discern_model(X_,Y_):
    weights = {
        "wc1":tf.Variable(tf.random_normal([3,3,1,64],stddev=0.1)),
        "wc2":tf.Variable(tf.random_normal([5,5,64,128],stddev=0.1)),
        "wd3":tf.Variable(tf.random_normal([7*7*128,1024],stddev=0.1)),
        "wd4": tf.Variable(tf.random_normal([1024, 12], stddev=0.1))
    }
    biases = {
        "bc1":tf.Variable(tf.random_normal([64],stddev=0.1)),
        "bc2":tf.Variable(tf.random_normal([128],stddev=0.1)),
        "bd3": tf.Variable(tf.random_normal([1024],stddev=0.1)),
        "bd4": tf.Variable(tf.random_normal([12],stddev=0.1))
    }
    x_input =  tf.reshape(X_,shape=[-1,28,28,1])

    # 第一层卷积层
    _conv1 = tf.nn.conv2d(x_input,weights["wc1"],strides=[1,1,1,1],padding="SAME")
    _conv1_ = tf.nn.relu(tf.nn.bias_add(_conv1,biases["bc1"]))
    # 第一层池化层
    _pool1 = tf.nn.max_pool(_conv1_,ksize=[1,2,2,1],strides=[1,2,2,1],padding="SAME")
    # 第一层失活层
    _pool1_dropout = tf.nn.dropout(_pool1,0.7)

    # 第二层卷积层
    _conv2 = tf.nn.conv2d(_pool1_dropout,weights["wc2"],strides=[1,1,1,1],padding="SAME")
    _conv2_ = tf.nn.relu(tf.nn.bias_add(_conv2,biases["bc2"]))
    # 第二层池化层
    _pool2 = tf.nn.max_pool(_conv2_,ksize=[1,2,2,1],strides=[1,2,2,1],padding="SAME")
    # 第二层失活层
    _pool2_dropout =  tf.nn.dropout(_pool2,0.7)

    # 使用全连接层提取抽象特征
    # 全连接层1
    _densel =  tf.reshape(_pool2_dropout,[-1,weights["wd3"].get_shape().as_list()[0]])
    _y1 = tf.nn.relu(tf.add(tf.matmul(_densel,weights["wd3"]),biases["bd3"]))
    _y2 = tf.nn.dropout(_y1,0.7)
    # 全连接层2
    out = tf.add(tf.matmul(_y2,weights["wd4"]),biases["bd4"])

    # 损失函数 loss
    loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits_v2(labels=Y_, logits=out))  # 计算交叉熵

    # 优化目标 optimizing
    optimizing = tf.train.AdamOptimizer(0.001).minimize(loss)  # 使用adam优化器来以0.0001的学习率来进行微调



    # 精确度 accuracy
    correct_prediction = tf.equal(tf.argmax(Y_, 1), tf.argmax(out, 1))  # 判断预测标签和实际标签是否匹配
    accuracy = tf.reduce_mean(tf.cast(correct_prediction, "float"))



    return {
        "loss":loss,
        "optimizing":optimizing,
        "accuracy":accuracy,
        "out":out
    }

批量训练方法:

# 开始准备训练cnn
X = tf.placeholder(tf.float32,[None,28,28,1])
# 这个12属于人脸类别,一共有几个id
Y = tf.placeholder(tf.float32, [None,12])


# 实例化模型
cnn_model = cnn_face_discern_model(X,Y)

loss,optimizing,accuracy,out = cnn_model["loss"],cnn_model["optimizing"],cnn_model["accuracy"],cnn_model["out"]


# 启动训练模型
bsize = 960/60

with tf.Session() as sess:
    # 实例所有参数
    sess.run(tf.global_variables_initializer())
    for epoch in range(100):
        for i in range(15):
            x_bsize,y_bsize = x_train[i*60:i*60+60,:,:,:],y_train[i*60:i*60+60,:]
            sess.run(optimizing,feed_dict={X:x_bsize,Y:y_bsize})

        if (epoch+1)%10==0:
            los = sess.run(loss,feed_dict={X:x_test,Y:y_test})
            acc = sess.run(accuracy,feed_dict={X:x_test,Y:y_test})

            print("epoch:%s loss:%s accuracy:%s"%(epoch,los,acc))

    score= sess.run(accuracy,feed_dict={X:x_test,Y:y_test})

    y_pred = sess.run(out,feed_dict={X:x_test})

    # 这个是类别,测试集预测出来的类别。
    y_pred = np.argmax(y_pred,axis=1)

    print("最后的精确度为:%s"%score)

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转载自www.cnblogs.com/wuzaipei/p/10474177.html