keras實現(xiàn)基于孿生網絡的圖片相似度計算方式
我就廢話不多說了,大家還是直接看代碼吧!
import keras
from keras.layers import Input,Dense,Conv2D
from keras.layers import MaxPooling2D,Flatten,Convolution2D
from keras.models import Model
import os
import numpy as np
from PIL import Image
from keras.optimizers import SGD
from scipy import misc
root_path = os.getcwd()
train_names = ['bear','blackswan','bus','camel','car','cows','dance','dog','hike','hoc','kite','lucia','mallerd','pigs','soapbox','stro','surf','swing','train','walking']
test_names = ['boat','dance-jump','drift-turn','elephant','libby']
def load_data(seq_names,data_number,seq_len):
#生成圖片對
print('loading data.....')
frame_num = 51
train_data1 = []
train_data2 = []
train_lab = []
count = 0
while count < data_number:
count = count + 1
pos_neg = np.random.randint(0,2)
if pos_neg==0:
seed1 = np.random.randint(0,seq_len)
seed2 = np.random.randint(0,seq_len)
while seed1 == seed2:
seed1 = np.random.randint(0,seq_len)
seed2 = np.random.randint(0,seq_len)
frame1 = np.random.randint(1,frame_num)
frame2 = np.random.randint(1,frame_num)
path1 = os.path.join(root_path,'data','simility_data',seq_names[seed1],str(frame1)+'.jpg')
path2 = os.path.join(root_path, 'data', 'simility_data', seq_names[seed2], str(frame2) + '.jpg')
image1 = np.array(misc.imresize(Image.open(path1),[224,224]))
image2 = np.array(misc.imresize(Image.open(path2),[224,224]))
train_data1.append(image1)
train_data2.append(image2)
train_lab.append(np.array(0))
else:
seed = np.random.randint(0,seq_len)
frame1 = np.random.randint(1, frame_num)
frame2 = np.random.randint(1, frame_num)
path1 = os.path.join(root_path, 'data', 'simility_data', seq_names[seed], str(frame1) + '.jpg')
path2 = os.path.join(root_path, 'data', 'simility_data', seq_names[seed], str(frame2) + '.jpg')
image1 = np.array(misc.imresize(Image.open(path1),[224,224]))
image2 = np.array(misc.imresize(Image.open(path2),[224,224]))
train_data1.append(image1)
train_data2.append(image2)
train_lab.append(np.array(1))
return np.array(train_data1),np.array(train_data2),np.array(train_lab)
def vgg_16_base(input_tensor):
net = Conv2D(64(3,3),activation='relu',padding='same',input_shape=(224,224,3))(input_tensor)
net = Convolution2D(64,(3,3),activation='relu',padding='same')(net)
net = MaxPooling2D((2,2),strides=(2,2))(net)
net = Convolution2D(128,(3,3),activation='relu',padding='same')(net)
net = Convolution2D(128,(3,3),activation='relu',padding='same')(net)
net= MaxPooling2D((2,2),strides=(2,2))(net)
net = Convolution2D(256,(3,3),activation='relu',padding='same')(net)
net = Convolution2D(256,(3,3),activation='relu',padding='same')(net)
net = Convolution2D(256,(3,3),activation='relu',padding='same')(net)
net = MaxPooling2D((2,2),strides=(2,2))(net)
net = Convolution2D(512,(3,3),activation='relu',padding='same')(net)
net = Convolution2D(512,(3,3),activation='relu',padding='same')(net)
net = Convolution2D(512,(3,3),activation='relu',padding='same')(net)
net = MaxPooling2D((2,2),strides=(2,2))(net)
net = Convolution2D(512,(3,3),activation='relu',padding='same')(net)
net = Convolution2D(512,(3,3),activation='relu',padding='same')(net)
net = Convolution2D(512,(3,3),activation='relu',padding='same')(net)
net = MaxPooling2D((2,2),strides=(2,2))(net)
net = Flatten()(net)
return net
def siamese(vgg_path=None,siamese_path=None):
input_tensor = Input(shape=(224,224,3))
vgg_model = Model(input_tensor,vgg_16_base(input_tensor))
if vgg_path:
vgg_model.load_weights(vgg_path)
input_im1 = Input(shape=(224,224,3))
input_im2 = Input(shape=(224,224,3))
out_im1 = vgg_model(input_im1)
out_im2 = vgg_model(input_im2)
diff = keras.layers.substract([out_im1,out_im2])
out = Dense(500,activation='relu')(diff)
out = Dense(1,activation='sigmoid')(out)
model = Model([input_im1,input_im2],out)
if siamese_path:
model.load_weights(siamese_path)
return model
train = True
if train:
model = siamese(siamese_path='model/simility/vgg.h5')
sgd = SGD(lr=1e-6,momentum=0.9,decay=1e-6,nesterov=True)
model.compile(optimizer=sgd,loss='mse',metrics=['accuracy'])
tensorboard = keras.callbacks.TensorBoard(histogram_freq=5,log_dir='log/simility',write_grads=True,write_images=True)
ckpt = keras.callbacks.ModelCheckpoint(os.path.join(root_path,'model','simility','vgg.h5'),
verbose=1,period=5)
train_data1,train_data2,train_lab = load_data(train_names,4000,20)
model.fit([train_data1,train_data2],train_lab,callbacks=[tensorboard,ckpt],batch_size=64,epochs=50)
else:
model = siamese(siamese_path='model/simility/vgg.h5')
test_im1,test_im2,test_labe = load_data(test_names,1000,5)
TP = 0
for i in range(1000):
im1 = np.expand_dims(test_im1[i],axis=0)
im2 = np.expand_dims(test_im2[i],axis=0)
lab = test_labe[i]
pre = model.predict([im1,im2])
if pre>0.9 and lab==1:
TP = TP + 1
if pre<0.9 and lab==0:
TP = TP + 1
print(float(TP)/1000)
輸入兩張圖片,標記1為相似,0為不相似。
損失函數(shù)用的是簡單的均方誤差,有待改成Siamese的對比損失。
總結:
1.隨機生成了幾組1000對的圖片,測試精度0.7左右,效果一般。
2.問題 1)數(shù)據加載沒有用生成器,還得繼續(xù)認真看看文檔 2)訓練時劃分驗證集的時候,訓練就會報錯,什么輸入維度的問題,暫時沒找到原因 3)輸入的shape好像必須給出數(shù)字,本想用shape= input_tensor.get_shape(),能訓練,不能保存模型,會報(NOT JSON Serializable,Dimension(None))類型錯誤
補充知識: keras 問答匹配孿生網絡文本匹配 RNN 帶有數(shù)據
用途:
這篇博客解釋了如何搭建一個簡單的匹配網絡。并且使用了keras的lambda層。在建立網絡之前需要對數(shù)據進行預處理。處理過后,文本轉變?yōu)閕d字符序列。將一對question,answer分別編碼可以得到兩個向量,在匹配層中比較兩個向量,計算相似度。
網絡圖示:

數(shù)據準備:
數(shù)據基于網上的淘寶客服對話數(shù)據,我也會放在我的下載頁面中。原數(shù)據是對話,我篩選了其中l(wèi)abel為1的對話。然后將對話拆解成QA對,q是用戶,a是客服。然后對于每個q,有一個a是匹配的,label為1.再選擇一個a,構成新的樣本,label為0.
超參數(shù):
比較簡單,具體看代碼就可以了。
# dialogue max pair q,a max_pair = 30000 # top k frequent word ,k MAX_FEATURES = 450 # fixed q,a length MAX_SENTENCE_LENGTH = 30 embedding_size = 100 batch_size = 600 # learning rate lr = 0.01 HIDDEN_LAYER_SIZE = n_hidden_units = 256 # neurons in hidden layer
細節(jié):
導入一些庫
# -*- coding: utf-8 -*- from keras.layers.core import Activation, Dense, Dropout, SpatialDropout1D from keras.layers.embeddings import Embedding from keras.layers.recurrent import LSTM from keras.preprocessing import sequence from sklearn.model_selection import train_test_split import collections import matplotlib.pyplot as plt import nltk import numpy as np import os import pandas as pd from alime_data import convert_dialogue_to_pair from parameter import MAX_SENTENCE_LENGTH,MAX_FEATURES,embedding_size,max_pair,batch_size,HIDDEN_LAYER_SIZE DATA_DIR = "../data" NUM_EPOCHS = 2 # Read training data and generate vocabulary maxlen = 0 num_recs = 0
數(shù)據準備,先統(tǒng)計詞頻,然后取出top N個常用詞,然后將句子轉換成 單詞id的序列。把句子中的有效id靠右邊放,將句子左邊補齊padding。然后分成訓練集和測試集
word_freqs = collections.Counter()
training_data = convert_dialogue_to_pair(max_pair)
num_recs = len([1 for r in training_data.iterrows()])
#for line in ftrain:
for line in training_data.iterrows():
label ,sentence_q = line[1]['label'],line[1]['sentence_q']
label ,sentence_a = line[1]['label'],line[1]['sentence_a']
words = nltk.word_tokenize(sentence_q.lower())#.decode("ascii", "ignore")
if len(words) > maxlen:
maxlen = len(words)
for word in words:
word_freqs[word] += 1
words = nltk.word_tokenize(sentence_a.lower())#.decode("ascii", "ignore")
if len(words) > maxlen:
maxlen = len(words)
for word in words:
word_freqs[word] += 1
#num_recs += 1
## Get some information about our corpus
# 1 is UNK, 0 is PAD
# We take MAX_FEATURES-1 featurs to accound for PAD
vocab_size = min(MAX_FEATURES, len(word_freqs)) + 2
word2index = {x[0]: i+2 for i, x in enumerate(word_freqs.most_common(MAX_FEATURES))}
word2index["PAD"] = 0
word2index["UNK"] = 1
index2word = {v:k for k, v in word2index.items()}
# convert sentences to sequences
X_q = np.empty((num_recs, ), dtype=list)
X_a = np.empty((num_recs, ), dtype=list)
y = np.zeros((num_recs, ))
i = 0
def chinese_split(x):
return x.split(' ')
for line in training_data.iterrows():
label ,sentence_q,sentence_a = line[1]['label'],line[1]['sentence_q'],line[1]['sentence_a']
#label, sentence = line.strip().split("\t")
#print(label,sentence)
#words = nltk.word_tokenize(sentence_q.lower())
words = chinese_split(sentence_q)
seqs = []
for word in words:
if word in word2index.keys():
seqs.append(word2index[word])
else:
seqs.append(word2index["UNK"])
X_q[i] = seqs
#print('add_q')
#words = nltk.word_tokenize(sentence_a.lower())
words = chinese_split(sentence_a)
seqs = []
for word in words:
if word in word2index.keys():
seqs.append(word2index[word])
else:
seqs.append(word2index["UNK"])
X_a[i] = seqs
y[i] = int(label)
i += 1
# Pad the sequences (left padded with zeros)
X_a = sequence.pad_sequences(X_a, maxlen=MAX_SENTENCE_LENGTH)
X_q = sequence.pad_sequences(X_q, maxlen=MAX_SENTENCE_LENGTH)
X = []
for i in range(len(X_a)):
concat = [X_q[i],X_a[i]]
X.append(concat)
# Split input into training and test
Xtrain, Xtest, ytrain, ytest = train_test_split(X, y, test_size=0.2,
random_state=42)
#print(Xtrain.shape, Xtest.shape, ytrain.shape, ytest.shape)
Xtrain_Q = [e[0] for e in Xtrain]
Xtrain_A = [e[1] for e in Xtrain]
Xtest_Q = [e[0] for e in Xtest]
Xtest_A = [e[1] for e in Xtest]
最后建立網絡。先定義兩個函數(shù),一個是句子編碼器,另一個是lambda層,計算兩個向量的絕對差。將QA分別用encoder處理得到兩個向量,把兩個向量放入lambda層。最后有了2*hidden size的一層,將這一層接一個dense層,接activation,得到分類概率。
from keras.layers.wrappers import Bidirectional
from keras.layers import Input,Lambda
from keras.models import Model
def encoder(inputs_seqs,rnn_hidden_size,dropout_rate):
x_embed = Embedding(vocab_size, embedding_size, input_length=MAX_SENTENCE_LENGTH)(inputs_seqs)
inputs_drop = SpatialDropout1D(0.2)(x_embed)
encoded_Q = Bidirectional(
LSTM(rnn_hidden_size, dropout=dropout_rate, recurrent_dropout=dropout_rate, name='RNN'))(inputs_drop)
return encoded_Q
def absolute_difference(vecs):
a,b =vecs
#d = a-b
return abs(a - b)
inputs_Q = Input(shape=(MAX_SENTENCE_LENGTH,), name="input")
# x_embed = Embedding(vocab_size, embedding_size, input_length=MAX_SENTENCE_LENGTH)(inputs_Q)
# inputs_drop = SpatialDropout1D(0.2)(x_embed)
# encoded_Q = Bidirectional(LSTM(HIDDEN_LAYER_SIZE, dropout=0.2, recurrent_dropout=0.2,name= 'RNN'))(inputs_drop)
inputs_A = Input(shape=(MAX_SENTENCE_LENGTH,), name="input_a")
# x_embed = Embedding(vocab_size, embedding_size, input_length=MAX_SENTENCE_LENGTH)(inputs_A)
# inputs_drop = SpatialDropout1D(0.2)(x_embed)
# encoded_A = Bidirectional(LSTM(HIDDEN_LAYER_SIZE, dropout=0.2, recurrent_dropout=0.2,name= 'RNN'))(inputs_drop)
encoded_Q = encoder(inputs_Q,HIDDEN_LAYER_SIZE,0.1)
encoded_A = encoder(inputs_A,HIDDEN_LAYER_SIZE,0.1)
# import tensorflow as tf
# difference = tf.subtract(encoded_Q, encoded_A)
# difference = tf.abs(difference)
similarity = Lambda(absolute_difference)([encoded_Q, encoded_A])
# x = concatenate([encoded_Q, encoded_A])
#
# matching_x = Dense(128)(x)
# matching_x = Activation("sigmoid")(matching_x)
polar = Dense(1)(similarity)
prop = Activation("sigmoid")(polar)
model = Model(inputs=[inputs_Q,inputs_A], outputs=prop)
model.compile(loss="binary_crossentropy", optimizer="adam",
metrics=["accuracy"])
training_history = model.fit([Xtrain_Q, Xtrain_A], ytrain, batch_size=batch_size,
epochs=NUM_EPOCHS,
validation_data=([Xtest_Q,Xtest_A], ytest))
# plot loss and accuracy
def plot(training_history):
plt.subplot(211)
plt.title("Accuracy")
plt.plot(training_history.history["acc"], color="g", label="Train")
plt.plot(training_history.history["val_acc"], color="b", label="Validation")
plt.legend(loc="best")
plt.subplot(212)
plt.title("Loss")
plt.plot(training_history.history["loss"], color="g", label="Train")
plt.plot(training_history.history["val_loss"], color="b", label="Validation")
plt.legend(loc="best")
plt.tight_layout()
plt.show()
# evaluate
score, acc = model.evaluate([Xtest_Q,Xtest_A], ytest, batch_size = batch_size)
print("Test score: %.3f, accuracy: %.3f" % (score, acc))
for i in range(25):
idx = np.random.randint(len(Xtest_Q))
#idx2 = np.random.randint(len(Xtest_A))
xtest_Q = Xtest_Q[idx].reshape(1,MAX_SENTENCE_LENGTH)
xtest_A = Xtest_A[idx].reshape(1,MAX_SENTENCE_LENGTH)
ylabel = ytest[idx]
ypred = model.predict([xtest_Q,xtest_A])[0][0]
sent_Q = " ".join([index2word[x] for x in xtest_Q[0].tolist() if x != 0])
sent_A = " ".join([index2word[x] for x in xtest_A[0].tolist() if x != 0])
print("%.0f\t%d\t%s\t%s" % (ypred, ylabel, sent_Q,sent_A))
最后是處理數(shù)據的函數(shù),寫在另一個文件里。
import nltk
from parameter import MAX_FEATURES,MAX_SENTENCE_LENGTH
import pandas as pd
from collections import Counter
def get_pair(number, dialogue):
pairs = []
for conversation in dialogue:
utterances = conversation[2:].strip('\n').split('\t')
# print(utterances)
# break
for i, utterance in enumerate(utterances):
if i % 2 != 0: continue
pairs.append([utterances[i], utterances[i + 1]])
if len(pairs) >= number:
return pairs
return pairs
def convert_dialogue_to_pair(k):
dialogue = open('dialogue_alibaba2.txt', encoding='utf-8', mode='r')
dialogue = dialogue.readlines()
dialogue = [p for p in dialogue if p.startswith('1')]
print(len(dialogue))
pairs = get_pair(k, dialogue)
# break
# print(pairs)
data = []
for p in pairs:
data.append([p[0], p[1], 1])
for i, p in enumerate(pairs):
data.append([p[0], pairs[(i + 8) % len(pairs)][1], 0])
df = pd.DataFrame(data, columns=['sentence_q', 'sentence_a', 'label'])
print(len(data))
return df
以上這篇keras實現(xiàn)基于孿生網絡的圖片相似度計算方式就是小編分享給大家的全部內容了,希望能給大家一個參考,也希望大家多多支持腳本之家。
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