Path: blob/master/Model-1/GapClassifier-Attention-RNN.ipynb
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Kernel: Python 3
CNN with Bidirctional RNN - Char Classification
Using TensorFlow
TODO
In [1]:
import numpy as np import pandas as pd import matplotlib.pyplot as plt import math import tensorflow as tf import tensorflow.contrib.seq2seq as seq2seq import cv2 %matplotlib notebook # Increase size of plots plt.rcParams['figure.figsize'] = (9.0, 5.0) # Helpers from ocr.helpers import implt from ocr.mlhelpers import TrainingPlot, DataSet from ocr.imgtransform import coordinates_remap from ocr.datahelpers import loadWordsData, correspondingShuffle from ocr.tfhelpers import Graph, create_cell tf.reset_default_graph() sess = tf.InteractiveSession() print("OpenCV: " + cv2.__version__) print("Numpy: " + np.__version__) print("TensorFlow: " + tf.__version__)
Out[1]:
OpenCV: 3.1.0
Numpy: 1.13.1
TensorFlow: 1.3.0
Loading Images
In [2]:
images, _, gaplines = loadWordsData(['data/words/'], loadGaplines=True)
Out[2]:
Loading words...
-> Number of words: 1008
Settings
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PAD = 0 # Value for PADding images POS = 1 # Values of positive and negative label 0/-1 NEG = 0 POS_SPAN = 1 # Number of positive values around true position (5 is too high) POS_WEIGHT = 10 # Weighting possitive values in loss counting slider_size = (60, 30) # Height is set to 60 by data and width should be even slider_step = 2 # Number of pixels slider moving N_INPUT = 1800 # Size of sequence input vector will depend on CNN num_buckets = 10 n_classes = 2 # Number of different outputs rnn_layers = 4 # 4 - 2 - 256 rnn_residual_layers = 2 # HAVE TO be smaller than encoder_layers rnn_units = 128 attention_size = 64 learning_rate = 1e-4 # 1e-4 dropout = 0.4 # Percentage of dopped out data train_set = 0.8 # Percentage of training data TRAIN_STEPS = 500000 # Number of training steps! TEST_ITER = 150 LOSS_ITER = 50 SAVE_ITER = 2000 BATCH_SIZE = 32 # EPOCH = 2000 # "Number" of batches in epoch
Dataset
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# Shuffle data images, gaplines = correspondingShuffle([images, gaplines]) for i in range(len(images)): # Add border and offset gaplines - RUN ONLY ONCE images[i] = cv2.copyMakeBorder(images[i], 0, 0, int(slider_size[1]/2), int(slider_size[1]/2), cv2.BORDER_CONSTANT, value=0) gaplines[i] += int(slider_size[1] / 2) # Image standardization same as tf.image.per_image_standardization for i in range(len(images)): images[i] = (images[i] - np.mean(images[i])) / max(np.std(images[i]), 1.0/math.sqrt(images[i].size)) # Split data on train and test dataset div = int(train_set * len(images)) trainImages = images[0:div] testImages = images[div:] trainGaplines = gaplines[0:div] testGaplines = gaplines[div:] print("Training images:", div) print("Testing images:", len(images) - div)
Out[4]:
Training images: 806
Testing images: 202
In [5]:
class BucketDataIterator(): """ Iterator for feeding seq2seq model during training """ def __init__(self, images, gaplines, gap_span, num_buckets=5, slider=(60, 30), slider_step=2, imgprocess=lambda x: x, train=True): self.train = train # self.slider = slider # self.slider_step = slider_step length = [(image.shape[1]-slider[1])//slider_step for image in images] # Creating indices from gaplines indices = gaplines - int(slider[1]/2) indices = indices // slider_step # Split images to sequence of vectors # + targets seq of labels per image in images seq images_seq = np.empty(len(images), dtype=object) targets_seq = np.empty(len(images), dtype=object) for i, img in enumerate(images): images_seq[i] = [imgprocess(img[:, loc * slider_step: loc * slider_step + slider[1]].flatten()) for loc in range(length[i])] targets_seq[i] = np.ones((length[i])) * NEG for offset in range(gap_span): ind = indices[i] + (-(offset % 2) * offset // 2) + ((1 - offset%2) * offset // 2) if ind[0] < 0: ind[0] = 0 if ind[-1] >= length[i]: ind[-1] = length[i] - 1 targets_seq[i][ind] = POS # Create pandas dataFrame and sort it by images seq lenght (length) # in_length == out_length self.dataFrame = pd.DataFrame({'length': length, 'images': images_seq, 'targets': targets_seq }).sort_values('length').reset_index(drop=True) bsize = int(len(images) / num_buckets) self.num_buckets = num_buckets # Create buckets by slicing parts by indexes self.buckets = [] for bucket in range(num_buckets-1): self.buckets.append(self.dataFrame.iloc[bucket * bsize: (bucket+1) * bsize]) self.buckets.append(self.dataFrame.iloc[(num_buckets-1) * bsize:]) self.buckets_size = [len(bucket) for bucket in self.buckets] # cursor[i] will be the cursor for the ith bucket self.cursor = np.array([0] * num_buckets) self.bucket_order = np.random.permutation(num_buckets) self.bucket_cursor = 0 self.shuffle() print("Iterator created.") def shuffle(self, idx=None): """ Shuffle idx bucket or each bucket separately """ for i in [idx] if idx is not None else range(self.num_buckets): self.buckets[i] = self.buckets[i].sample(frac=1).reset_index(drop=True) self.cursor[i] = 0 def next_batch(self, batch_size): """ Creates next training batch of size: batch_size Retruns: image seq, letter seq, image seq lengths, letter seq lengths """ i_bucket = self.bucket_order[self.bucket_cursor] # Increment cursor and shuffle in case of new round self.bucket_cursor = (self.bucket_cursor + 1) % self.num_buckets if self.bucket_cursor == 0: self.bucket_order = np.random.permutation(self.num_buckets) if self.cursor[i_bucket] + batch_size > self.buckets_size[i_bucket]: self.shuffle(i_bucket) # Handle too big batch sizes if (batch_size > self.buckets_size[i_bucket]): batch_size = self.buckets_size[i_bucket] res = self.buckets[i_bucket].iloc[self.cursor[i_bucket]: self.cursor[i_bucket]+batch_size] self.cursor[i_bucket] += batch_size # PAD input sequence and output # Pad sequences with <PAD> to same length max_length = max(res['length']) input_seq = np.zeros((batch_size, max_length, N_INPUT), dtype=np.float32) for i, img in enumerate(res['images']): input_seq[i][:res['length'].values[i]] = img input_seq = input_seq.swapaxes(0, 1) # Need to pad according to the maximum length output sequence targets = np.ones([batch_size, max_length], dtype=np.float32) * PAD for i, target in enumerate(targets): target[:res['length'].values[i]] = res['targets'].values[i] return input_seq, targets, res['length'].values def next_feed(self, size): """ Create feed directly for model training """ (inputs_, targets_, length_) = self.next_batch(size) return { inputs: inputs_, targets: targets_, length: length_, keep_prob: (1.0 - dropout) if self.train else 1.0 }
In [6]:
# Create iterator for feeding BiRNN train_iterator = BucketDataIterator(trainImages, trainGaplines, POS_SPAN, num_buckets, slider_size, slider_step, train=True) test_iterator = BucketDataIterator(testImages, testGaplines, POS_SPAN, 2, slider_size, slider_step, train=False)
Out[6]:
Iterator created.
Iterator created.
Create classifier
Inputs
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# Input placehodlers # N_INPUT -> size of vector representing one image in sequence # Inputs shape (max_seq_length, batch_size, vec_size) - time major inputs = tf.placeholder(shape=(None, None, N_INPUT), dtype=tf.float32, name='inputs') length = tf.placeholder(shape=(None,), dtype=tf.int32, # EDITED: tf.int32 name='length') # required for training, not required for testing and application targets = tf.placeholder(shape=(None, None), dtype=tf.int64, name='targets') # Dropout value keep_prob = tf.placeholder(tf.float32, name='keep_prob') sequence_size, batch_size, _ = tf.unstack(tf.shape(inputs))
Standardization + CNN
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# Help functions for standard layers def conv2d(x, W, name=None): return tf.nn.conv2d(x, W, strides=[1, 1, 1, 1], padding='SAME', name=name) def max_pool_2x2(x, name=None): return tf.nn.max_pool(x, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='SAME', name=name) # 1. Layer - Convulation variables W_conv1 = tf.get_variable('W_conv1', shape=[5, 5, 1, 4], initializer=tf.contrib.layers.xavier_initializer()) b_conv1 = tf.Variable(tf.constant(0.1, shape=[4]), name='b_conv1') # 3. Layer - Convulation variables W_conv2 = tf.get_variable('W_conv2', shape=[5, 5, 4, 8], initializer=tf.contrib.layers.xavier_initializer()) b_conv2 = tf.Variable(tf.constant(0.1, shape=[8]), name='b_conv2') def CNN(x): # 1. Layer - Convulation h_conv1 = tf.nn.relu(conv2d(x, W_conv1) + b_conv1, name='h_conv1') # 2. Layer - Max Pool h_pool1 = max_pool_2x2(h_conv1, name='h_pool1') # 3. Layer - Convulation h_conv2 = tf.nn.relu(conv2d(h_pool1, W_conv2) + b_conv2, name='h_conv2') # 4. Layer - Max Pool return max_pool_2x2(h_conv2, name='h_pool2') # Input images CNN inpts = tf.map_fn( lambda seq: tf.map_fn( lambda img: tf.reshape( CNN(tf.reshape(img, [1, slider_size[0], slider_size[1], 1])), [-1]), seq), inputs, dtype=tf.float32)
Attention
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# attention_states: size [batch_size, max_time, num_units] attention_states = tf.transpose(inpts, [1, 0, 2]) # Create an attention mechanism attention_mechanism = tf.contrib.seq2seq.LuongAttention( rnn_units, attention_states, memory_sequence_length=length) final_cell = create_cell(rnn_units, 2*rnn_layers, 2*rnn_residual_layers, is_dropout=True, keep_prob=keep_prob) final_cell = seq2seq.AttentionWrapper( final_cell, attention_mechanism, attention_layer_size=attention_size) final_initial_state = final_cell.zero_state(batch_size, tf.float32) attention_output, _ = tf.nn.dynamic_rnn( cell=final_cell, inputs=attention_states, sequence_length=length, # initial_state=final_initial_state, dtype = tf.float32)
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pred = tf.layers.dense(inputs=attention_output, units=2, name='pred') prediction = tf.argmax(pred, axis=-1, name='prediction')
Optimizer
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# Define loss and optimizer # loss = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(logits=pred, labels=targets), name='loss') weights = tf.multiply(targets, POS_WEIGHT) + 1 loss = tf.reduce_mean(tf.losses.sparse_softmax_cross_entropy( logits=pred, labels=targets, weights=weights), name='loss') train_step = tf.train.AdamOptimizer(learning_rate=learning_rate).minimize(loss, name='train_step') # Evaluate model correct_pred = tf.equal(prediction, targets) accuracy = tf.reduce_mean(tf.cast(correct_pred, tf.float32)) # accuracy = tf.reduce_mean(prediction * targets) # Testing for only zero predictions
Training
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sess.run(tf.global_variables_initializer()) saver = tf.train.Saver() # Creat plot for live stats ploting trainPlot = TrainingPlot(TRAIN_STEPS, TEST_ITER, LOSS_ITER) try: for i_batch in range(TRAIN_STEPS): fd = train_iterator.next_feed(BATCH_SIZE) train_step.run(fd) if i_batch % LOSS_ITER == 0: # Plotting loss tmpLoss = loss.eval(fd) trainPlot.updateCost(tmpLoss, i_batch // LOSS_ITER) if i_batch % TEST_ITER == 0: # Plotting accuracy fd_test = test_iterator.next_feed(BATCH_SIZE) accTest = accuracy.eval(fd_test) accTrain = accuracy.eval(fd) trainPlot.updateAcc(accTest, accTrain, i_batch // TEST_ITER) if i_batch % SAVE_ITER == 0: saver.save(sess, 'models/gap-clas/A-RNN/model') # if i_batch % EPOCH == 0: # fd_test = test_iterator.next_feed(BATCH_SIZE) # print('batch %r - loss: %r' % (i_batch, sess.run(loss, fd_test))) # predict_, target_ = sess.run([pred, targets], fd_test) # for i, (inp, pred) in enumerate(zip(target_, predict_)): # print(' expected > {}'.format(inp)) # print(' predicted > {}'.format(pred)) # break # print() except KeyboardInterrupt: saver.save(sess, 'models/gap-clas/A-RNN/model') print('Training interrupted, model saved.') fd_test = test_iterator.next_feed(2*BATCH_SIZE) accTest = accuracy.eval(fd_test) print("Training finished with accuracy:", accTest)
Out[12]:
<IPython.core.display.Javascript object>
Training interrupted, model saved.
Training finished with accuracy: 0.954117
In [26]:
% matplotlib inline num_examples = 5 # Shuffle test images testImages = testImages[np.random.permutation(len(testImages))] imgs = testImages[:num_examples] # Split images to sequence of vectors length = [(image.shape[1]-slider_size[1])//slider_step for image in imgs] images_seq = np.empty(num_examples, dtype=object) for i, img in enumerate(imgs): images_seq[i] = np.array([img[:, loc * slider_step: loc * slider_step + slider_size[1]].flatten() for loc in range(length[i])], dtype=np.float32) # Create predictions using trained model test_pred = [] for i, inpt in enumerate(images_seq): inpt = np.reshape(inpt, (inpt.shape[0], 1, inpt.shape[1])) img = imgs[i].copy() # img = cv2.cvtColor(imgs[i].astype(np.float32), cv2.COLOR_GRAY2RGB) pred = prediction.eval({'inputs:0': inpt, 'length:0': [len(inpt)], 'keep_prob:0': 1.0}) for pos, g in enumerate(pred[0]): if g == 1: cv2.line(img, ((int)(15 + pos*slider_step), 0), ((int)(15 + pos*slider_step), slider_size[0]), 1, 1) implt(img, 'gray', t=str(i))
Out[26]:
