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keras孿生網(wǎng)絡(luò)的圖片相似度怎么計(jì)算?

發(fā)布時(shí)間:2020-06-23 16:52:33 來源:億速云 閱讀:153 作者:清晨 欄目:開發(fā)技術(shù)

不懂keras孿生網(wǎng)絡(luò)的圖片相似度怎么計(jì)算??其實(shí)想解決這個(gè)問題也不難,下面讓小編帶著大家一起學(xué)習(xí)怎么去解決,希望大家閱讀完這篇文章后大所收獲。

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)
      path2 = os.path.join(root_path,'data','simility_data',seq_names[seed1],str(frame1)+'.jpg')
      path3 = os.path.join(root_path, 'data', 'simility_data', seq_names[seed2], str(frame2) + '.jpg')
      image1 = np.array(misc.imresize(Image.open(path2),[224,224]))
      image2 = np.array(misc.imresize(Image.open(path3),[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)
     path2 = os.path.join(root_path, 'data', 'simility_data', seq_names[seed], str(frame1) + '.jpg')
     path3 = os.path.join(root_path, 'data', 'simility_data', seq_names[seed], str(frame2) + '.jpg')
     image1 = np.array(misc.imresize(Image.open(path2),[224,224]))
     image2 = np.array(misc.imresize(Image.open(path3),[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.h6')
  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.h6'),
                    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.h6')
  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(biāo)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(jié):

1.隨機(jī)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(jù)加載沒有用生成器,還得繼續(xù)認(rèn)真看看文檔 2)訓(xùn)練時(shí)劃分驗(yàn)證集的時(shí)候,訓(xùn)練就會(huì)報(bào)錯(cuò),什么輸入維度的問題,暫時(shí)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(xùn)練,不能保存模型,會(huì)報(bào)(NOT JSON Serializable,Dimension(None))類型錯(cuò)誤

補(bǔ)充知識(shí): keras 問答匹配孿生網(wǎng)絡(luò)文本匹配 RNN 帶有數(shù)據(jù)

用途:

這篇博客解釋了如何搭建一個(gè)簡單的匹配網(wǎng)絡(luò)。并且使用了keras的lambda層。在建立網(wǎng)絡(luò)之前需要對數(shù)據(jù)進(jìn)行預(yù)處理。處理過后,文本轉(zhuǎn)變?yōu)閕d字符序列。將一對question,answer分別編碼可以得到兩個(gè)向量,在匹配層中比較兩個(gè)向量,計(jì)算相似度。

網(wǎng)絡(luò)圖示:

keras孿生網(wǎng)絡(luò)的圖片相似度怎么計(jì)算?

數(shù)據(jù)準(zhǔn)備:

數(shù)據(jù)基于網(wǎng)上的淘寶客服對話數(shù)據(jù),我也會(huì)放在我的下載頁面中。原數(shù)據(jù)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(gè)q,有一個(gè)a是匹配的,label為1.再選擇一個(gè)a,構(gòu)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(xì)節(jié):

導(dǎo)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(jù)準(zhǔn)備,先統(tǒng)計(jì)詞頻,然后取出top N個(gè)常用詞,然后將句子轉(zhuǎn)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(bǔ)齊padding。然后分成訓(xùn)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(wǎng)絡(luò)。先定義兩個(gè)函數(shù),一個(gè)是句子編碼器,另一個(gè)是lambda層,計(jì)算兩個(gè)向量的絕對差。將QA分別用encoder處理得到兩個(gè)向量,把兩個(gè)向量放入lambda層。最后有了2*hidden size的一層,將這一層接一個(gè)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(jù)的函數(shù),寫在另一個(gè)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

感謝你能夠認(rèn)真閱讀完這篇文章,希望小編分享keras孿生網(wǎng)絡(luò)的圖片相似度怎么計(jì)算?內(nèi)容對大家有幫助,同時(shí)也希望大家多多支持億速云,關(guān)注億速云行業(yè)資訊頻道,遇到問題就找億速云,詳細(xì)的解決方法等著你來學(xué)習(xí)!

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