Open source the image-to-text model based on the "Show and Tell" paper.

im2txt/im2txt/ops/image_embedding_test.py

+# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+"""Tests for tensorflow_models.im2txt.ops.image_embedding."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+
+import tensorflow as tf
+
+from im2txt.ops import image_embedding
+
+
+class InceptionV3Test(tf.test.TestCase):
+
+  def setUp(self):
+    super(InceptionV3Test, self).setUp()
+
+    batch_size = 4
+    height = 299
+    width = 299
+    num_channels = 3
+    self._images = tf.placeholder(tf.float32,
+                                  [batch_size, height, width, num_channels])
+    self._batch_size = batch_size
+
+  def _countInceptionParameters(self):
+    """Counts the number of parameters in the inception model at top scope."""
+    counter = {}
+    for v in tf.all_variables():
+      name_tokens = v.op.name.split("/")
+      if name_tokens[0] == "InceptionV3":
+        name = "InceptionV3/" + name_tokens[1]
+        num_params = v.get_shape().num_elements()
+        assert num_params
+        counter[name] = counter.get(name, 0) + num_params
+    return counter
+
+  def _verifyParameterCounts(self):
+    """Verifies the number of parameters in the inception model."""
+    param_counts = self._countInceptionParameters()
+    expected_param_counts = {
+        "InceptionV3/Conv2d_1a_3x3": 960,
+        "InceptionV3/Conv2d_2a_3x3": 9312,
+        "InceptionV3/Conv2d_2b_3x3": 18624,
+        "InceptionV3/Conv2d_3b_1x1": 5360,
+        "InceptionV3/Conv2d_4a_3x3": 138816,
+        "InceptionV3/Mixed_5b": 256368,
+        "InceptionV3/Mixed_5c": 277968,
+        "InceptionV3/Mixed_5d": 285648,
+        "InceptionV3/Mixed_6a": 1153920,
+        "InceptionV3/Mixed_6b": 1298944,
+        "InceptionV3/Mixed_6c": 1692736,
+        "InceptionV3/Mixed_6d": 1692736,
+        "InceptionV3/Mixed_6e": 2143872,
+        "InceptionV3/Mixed_7a": 1699584,
+        "InceptionV3/Mixed_7b": 5047872,
+        "InceptionV3/Mixed_7c": 6080064,
+    }
+    self.assertDictEqual(expected_param_counts, param_counts)
+
+  def _assertCollectionSize(self, expected_size, collection):
+    actual_size = len(tf.get_collection(collection))
+    if expected_size != actual_size:
+      self.fail("Found %d items in collection %s (expected %d)." %
+                (actual_size, collection, expected_size))
+
+  def testTrainableTrueIsTrainingTrue(self):
+    embeddings = image_embedding.inception_v3(
+        self._images, trainable=True, is_training=True)
+    self.assertEqual([self._batch_size, 2048], embeddings.get_shape().as_list())
+
+    self._verifyParameterCounts()
+    self._assertCollectionSize(376, tf.GraphKeys.VARIABLES)
+    self._assertCollectionSize(188, tf.GraphKeys.TRAINABLE_VARIABLES)
+    self._assertCollectionSize(188, tf.GraphKeys.UPDATE_OPS)
+    self._assertCollectionSize(94, tf.GraphKeys.REGULARIZATION_LOSSES)
+    self._assertCollectionSize(0, tf.GraphKeys.LOSSES)
+    self._assertCollectionSize(23, tf.GraphKeys.SUMMARIES)
+
+  def testTrainableTrueIsTrainingFalse(self):
+    embeddings = image_embedding.inception_v3(
+        self._images, trainable=True, is_training=False)
+    self.assertEqual([self._batch_size, 2048], embeddings.get_shape().as_list())
+
+    self._verifyParameterCounts()
+    self._assertCollectionSize(376, tf.GraphKeys.VARIABLES)
+    self._assertCollectionSize(188, tf.GraphKeys.TRAINABLE_VARIABLES)
+    self._assertCollectionSize(0, tf.GraphKeys.UPDATE_OPS)
+    self._assertCollectionSize(94, tf.GraphKeys.REGULARIZATION_LOSSES)
+    self._assertCollectionSize(0, tf.GraphKeys.LOSSES)
+    self._assertCollectionSize(23, tf.GraphKeys.SUMMARIES)
+
+  def testTrainableFalseIsTrainingTrue(self):
+    embeddings = image_embedding.inception_v3(
+        self._images, trainable=False, is_training=True)
+    self.assertEqual([self._batch_size, 2048], embeddings.get_shape().as_list())
+
+    self._verifyParameterCounts()
+    self._assertCollectionSize(376, tf.GraphKeys.VARIABLES)
+    self._assertCollectionSize(0, tf.GraphKeys.TRAINABLE_VARIABLES)
+    self._assertCollectionSize(0, tf.GraphKeys.UPDATE_OPS)
+    self._assertCollectionSize(0, tf.GraphKeys.REGULARIZATION_LOSSES)
+    self._assertCollectionSize(0, tf.GraphKeys.LOSSES)
+    self._assertCollectionSize(23, tf.GraphKeys.SUMMARIES)
+
+  def testTrainableFalseIsTrainingFalse(self):
+    embeddings = image_embedding.inception_v3(
+        self._images, trainable=False, is_training=False)
+    self.assertEqual([self._batch_size, 2048], embeddings.get_shape().as_list())
+
+    self._verifyParameterCounts()
+    self._assertCollectionSize(376, tf.GraphKeys.VARIABLES)
+    self._assertCollectionSize(0, tf.GraphKeys.TRAINABLE_VARIABLES)
+    self._assertCollectionSize(0, tf.GraphKeys.UPDATE_OPS)
+    self._assertCollectionSize(0, tf.GraphKeys.REGULARIZATION_LOSSES)
+    self._assertCollectionSize(0, tf.GraphKeys.LOSSES)
+    self._assertCollectionSize(23, tf.GraphKeys.SUMMARIES)
+
+
+if __name__ == "__main__":
+  tf.test.main()

im2txt/im2txt/ops/image_processing.py

+# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+"""Helper functions for image preprocessing."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+
+import tensorflow as tf
+
+
+def distort_image(image, thread_id):
+  """Perform random distortions on an image.
+
+  Args:
+    image: A float32 Tensor of shape [height, width, 3] with values in [0, 1).
+    thread_id: Preprocessing thread id used to select the ordering of color
+      distortions. There should be a multiple of 2 preprocessing threads.
+
+  Returns:
+    distorted_image: A float32 Tensor of shape [height, width, 3] with values in
+      [0, 1].
+  """
+  # Randomly flip horizontally.
+  with tf.name_scope("flip_horizontal", values=[image]):
+    image = tf.image.random_flip_left_right(image)
+
+  # Randomly distort the colors based on thread id.
+  color_ordering = thread_id % 2
+  with tf.name_scope("distort_color", values=[image]):
+    if color_ordering == 0:
+      image = tf.image.random_brightness(image, max_delta=32. / 255.)
+      image = tf.image.random_saturation(image, lower=0.5, upper=1.5)
+      image = tf.image.random_hue(image, max_delta=0.032)
+      image = tf.image.random_contrast(image, lower=0.5, upper=1.5)
+    elif color_ordering == 1:
+      image = tf.image.random_brightness(image, max_delta=32. / 255.)
+      image = tf.image.random_contrast(image, lower=0.5, upper=1.5)
+      image = tf.image.random_saturation(image, lower=0.5, upper=1.5)
+      image = tf.image.random_hue(image, max_delta=0.032)
+
+    # The random_* ops do not necessarily clamp.
+    image = tf.clip_by_value(image, 0.0, 1.0)
+
+  return image
+
+
+def process_image(encoded_image,
+                  is_training,
+                  height,
+                  width,
+                  resize_height=346,
+                  resize_width=346,
+                  thread_id=0,
+                  image_format="jpeg"):
+  """Decode an image, resize and apply random distortions.
+
+  In training, images are distorted slightly differently depending on thread_id.
+
+  Args:
+    encoded_image: String Tensor containing the image.
+    is_training: Boolean; whether preprocessing for training or eval.
+    height: Height of the output image.
+    width: Width of the output image.
+    resize_height: If > 0, resize height before crop to final dimensions.
+    resize_width: If > 0, resize width before crop to final dimensions.
+    thread_id: Preprocessing thread id used to select the ordering of color
+      distortions. There should be a multiple of 2 preprocessing threads.
+    image_format: "jpeg" or "png".
+
+  Returns:
+    A float32 Tensor of shape [height, width, 3] with values in [-1, 1].
+
+  Raises:
+    ValueError: If image_format is invalid.
+  """
+  # Helper function to log an image summary to the visualizer. Summaries are
+  # only logged in thread 0.
+  def image_summary(name, image):
+    if not thread_id:
+      tf.image_summary(name, tf.expand_dims(image, 0))
+
+  # Decode image into a float32 Tensor of shape [?, ?, 3] with values in [0, 1).
+  with tf.name_scope("decode", values=[encoded_image]):
+    if image_format == "jpeg":
+      image = tf.image.decode_jpeg(encoded_image, channels=3)
+    elif image_format == "png":
+      image = tf.image.decode_png(encoded_image, channels=3)
+    else:
+      raise ValueError("Invalid image format: %s" % image_format)
+  image = tf.image.convert_image_dtype(image, dtype=tf.float32)
+  image_summary("original_image", image)
+
+  # Resize image.
+  assert (resize_height > 0) == (resize_width > 0)
+  if resize_height:
+    image = tf.image.resize_images(image,
+                                   new_height=resize_height,
+                                   new_width=resize_width,
+                                   method=tf.image.ResizeMethod.BILINEAR)
+
+  # Crop to final dimensions.
+  if is_training:
+    image = tf.random_crop(image, [height, width, 3])
+  else:
+    # Central crop, assuming resize_height > height, resize_width > width.
+    image = tf.image.resize_image_with_crop_or_pad(image, height, width)
+
+  image_summary("resized_image", image)
+
+  # Randomly distort the image.
+  if is_training:
+    image = distort_image(image, thread_id)
+
+  image_summary("final_image", image)
+
+  # Rescale to [-1,1] instead of [0, 1]
+  image = tf.sub(image, 0.5)
+  image = tf.mul(image, 2.0)
+  return image

im2txt/im2txt/ops/inputs.py

+# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+"""Input ops."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+
+import tensorflow as tf
+
+
+def parse_sequence_example(serialized, image_feature, caption_feature):
+  """Parses a tensorflow.SequenceExample into an image and caption.
+
+  Args:
+    serialized: A scalar string Tensor; a single serialized SequenceExample.
+    image_feature: Name of SequenceExample context feature containing image
+      data.
+    caption_feature: Name of SequenceExample feature list containing integer
+      captions.
+
+  Returns:
+    encoded_image: A scalar string Tensor containing a JPEG encoded image.
+    caption: A 1-D uint64 Tensor with dynamically specified length.
+  """
+  context, sequence = tf.parse_single_sequence_example(
+      serialized,
+      context_features={
+          image_feature: tf.FixedLenFeature([], dtype=tf.string)
+      },
+      sequence_features={
+          caption_feature: tf.FixedLenSequenceFeature([], dtype=tf.int64),
+      })
+
+  encoded_image = context[image_feature]
+  caption = sequence[caption_feature]
+  return encoded_image, caption
+
+
+def prefetch_input_data(reader,
+                        file_pattern,
+                        is_training,
+                        batch_size,
+                        values_per_shard,
+                        input_queue_capacity_factor=16,
+                        num_reader_threads=1,
+                        shard_queue_name="filename_queue",
+                        value_queue_name="input_queue"):
+  """Prefetches string values from disk into an input queue.
+
+  In training the capacity of the queue is important because a larger queue
+  means better mixing of training examples between shards. The minimum number of
+  values kept in the queue is values_per_shard * input_queue_capacity_factor,
+  where input_queue_memory factor should be chosen to trade-off better mixing
+  with memory usage.
+
+  Args:
+    reader: Instance of tf.ReaderBase.
+    file_pattern: Comma-separated list of file patterns (e.g.
+        /tmp/train_data-?????-of-00100).
+    is_training: Boolean; whether prefetching for training or eval.
+    batch_size: Model batch size used to determine queue capacity.
+    values_per_shard: Approximate number of values per shard.
+    input_queue_capacity_factor: Minimum number of values to keep in the queue
+      in multiples of values_per_shard. See comments above.
+    num_reader_threads: Number of reader threads to fill the queue.
+    shard_queue_name: Name for the shards filename queue.
+    value_queue_name: Name for the values input queue.
+
+  Returns:
+    A Queue containing prefetched string values.
+  """
+  data_files = []
+  for pattern in file_pattern.split(","):
+    data_files.extend(tf.gfile.Glob(pattern))
+  if not data_files:
+    tf.logging.fatal("Found no input files matching %s", file_pattern)
+  else:
+    tf.logging.info("Prefetching values from %d files matching %s",
+                    len(data_files), file_pattern)
+
+  if is_training:
+    filename_queue = tf.train.string_input_producer(
+        data_files, shuffle=True, capacity=16, name=shard_queue_name)
+    min_queue_examples = values_per_shard * input_queue_capacity_factor
+    capacity = min_queue_examples + 100 * batch_size
+    values_queue = tf.RandomShuffleQueue(
+        capacity=capacity,
+        min_after_dequeue=min_queue_examples,
+        dtypes=[tf.string],
+        name="random_" + value_queue_name)
+  else:
+    filename_queue = tf.train.string_input_producer(
+        data_files, shuffle=False, capacity=1, name=shard_queue_name)
+    capacity = values_per_shard + 3 * batch_size
+    values_queue = tf.FIFOQueue(
+        capacity=capacity, dtypes=[tf.string], name="fifo_" + value_queue_name)
+
+  enqueue_ops = []
+  for _ in range(num_reader_threads):
+    _, value = reader.read(filename_queue)
+    enqueue_ops.append(values_queue.enqueue([value]))
+  tf.train.queue_runner.add_queue_runner(tf.train.queue_runner.QueueRunner(
+      values_queue, enqueue_ops))
+  tf.scalar_summary(
+      "queue/%s/fraction_of_%d_full" % (values_queue.name, capacity),
+      tf.cast(values_queue.size(), tf.float32) * (1. / capacity))
+
+  return values_queue
+
+
+def batch_with_dynamic_pad(images_and_captions,
+                           batch_size,
+                           queue_capacity,
+                           add_summaries=True):
+  """Batches input images and captions.
+
+  This function splits the caption into an input sequence and a target sequence,
+  where the target sequence is the input sequence right-shifted by 1. Input and
+  target sequences are batched and padded up to the maximum length of sequences
+  in the batch. A mask is created to distinguish real words from padding words.
+
+  Example:
+    Actual captions in the batch ('-' denotes padded character):
+      [
+        [ 1 2 5 4 5 ],
+        [ 1 2 3 4 - ],
+        [ 1 2 3 - - ],
+      ]
+
+    input_seqs:
+      [
+        [ 1 2 3 4 ],
+        [ 1 2 3 - ],
+        [ 1 2 - - ],
+      ]
+
+    target_seqs:
+      [
+        [ 2 3 4 5 ],
+        [ 2 3 4 - ],
+        [ 2 3 - - ],
+      ]
+
+    mask:
+      [
+        [ 1 1 1 1 ],
+        [ 1 1 1 0 ],
+        [ 1 1 0 0 ],
+      ]
+
+  Args:
+    images_and_captions: A list of pairs [image, caption], where image is a
+      Tensor of shape [height, width, channels] and caption is a 1-D Tensor of
+      any length. Each pair will be processed and added to the queue in a
+      separate thread.
+    batch_size: Batch size.
+    queue_capacity: Queue capacity.
+    add_summaries: If true, add caption length summaries.
+
+  Returns:
+    images: A Tensor of shape [batch_size, height, width, channels].
+    input_seqs: An int32 Tensor of shape [batch_size, padded_length].
+    target_seqs: An int32 Tensor of shape [batch_size, padded_length].
+    mask: An int32 0/1 Tensor of shape [batch_size, padded_length].
+  """
+  enqueue_list = []
+  for image, caption in images_and_captions:
+    caption_length = tf.shape(caption)[0]
+    input_length = tf.expand_dims(tf.sub(caption_length, 1), 0)
+
+    input_seq = tf.slice(caption, [0], input_length)
+    target_seq = tf.slice(caption, [1], input_length)
+    indicator = tf.ones(input_length, dtype=tf.int32)
+    enqueue_list.append([image, input_seq, target_seq, indicator])
+
+  images, input_seqs, target_seqs, mask = tf.train.batch_join(
+      enqueue_list,
+      batch_size=batch_size,
+      capacity=queue_capacity,
+      dynamic_pad=True,
+      name="batch_and_pad")
+
+  if add_summaries:
+    lengths = tf.add(tf.reduce_sum(mask, 1), 1)
+    tf.scalar_summary("caption_length/batch_min", tf.reduce_min(lengths))
+    tf.scalar_summary("caption_length/batch_max", tf.reduce_max(lengths))
+    tf.scalar_summary("caption_length/batch_mean", tf.reduce_mean(lengths))
+
+  return images, input_seqs, target_seqs, mask

im2txt/im2txt/run_inference.py

+# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+r"""Generate captions for images using default beam search parameters."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import math
+import os
+
+
+import tensorflow as tf
+
+from im2txt import configuration
+from im2txt import inference_wrapper
+from im2txt.inference_utils import caption_generator
+from im2txt.inference_utils import vocabulary
+
+FLAGS = tf.flags.FLAGS
+
+tf.flags.DEFINE_string("checkpoint_path", "",
+                       "Model checkpoint file or directory containing a "
+                       "model checkpoint file.")
+tf.flags.DEFINE_string("vocab_file", "", "Text file containing the vocabulary.")
+tf.flags.DEFINE_string("input_files", "",
+                       "File pattern or comma-separated list of file patterns "
+                       "of image files.")
+
+
+def main(_):
+  # Build the inference graph.
+  g = tf.Graph()
+  with g.as_default():
+    model = inference_wrapper.InferenceWrapper()
+    restore_fn = model.build_graph_from_config(configuration.ModelConfig(),
+                                               FLAGS.checkpoint_path)
+  g.finalize()
+
+  # Create the vocabulary.
+  vocab = vocabulary.Vocabulary(FLAGS.vocab_file)
+
+  filenames = []
+  for file_pattern in FLAGS.input_files.split(","):
+    filenames.extend(tf.gfile.Glob(file_pattern))
+  tf.logging.info("Running caption generation on %d files matching %s",
+                  len(filenames), FLAGS.input_files)
+
+  with tf.Session(graph=g) as sess:
+    # Load the model from checkpoint.
+    restore_fn(sess)
+
+    # Prepare the caption generator. Here we are implicitly using the default
+    # beam search parameters. See caption_generator.py for a description of the
+    # available beam search parameters.
+    generator = caption_generator.CaptionGenerator(model, vocab)
+
+    for filename in filenames:
+      with tf.gfile.GFile(filename, "r") as f:
+        image = f.read()
+      captions = generator.beam_search(sess, image)
+      print("Captions for image %s:" % os.path.basename(filename))
+      for i, caption in enumerate(captions):
+        # Ignore begin and end words.
+        sentence = [vocab.id_to_word(w) for w in caption.sentence[1:-1]]
+        sentence = " ".join(sentence)
+        print("  %d) %s (p=%f)" % (i, sentence, math.exp(caption.logprob)))
+
+
+if __name__ == "__main__":
+  tf.app.run()

im2txt/im2txt/show_and_tell_model.py

+# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+"""Image-to-text implementation based on http://arxiv.org/abs/1411.4555.
+
+"Show and Tell: A Neural Image Caption Generator"
+Oriol Vinyals, Alexander Toshev, Samy Bengio, Dumitru Erhan
+"""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+
+import tensorflow as tf
+
+from im2txt.ops import image_embedding
+from im2txt.ops import image_processing
+from im2txt.ops import inputs as input_ops
+
+
+class ShowAndTellModel(object):
+  """Image-to-text implementation based on http://arxiv.org/abs/1411.4555.
+
+  "Show and Tell: A Neural Image Caption Generator"
+  Oriol Vinyals, Alexander Toshev, Samy Bengio, Dumitru Erhan
+  """
+
+  def __init__(self, config, mode, train_inception=False):
+    """Basic setup.
+
+    Args:
+      config: Object containing configuration parameters.
+      mode: "train", "eval" or "inference".
+      train_inception: Whether the inception submodel variables are trainable.
+    """
+    assert mode in ["train", "eval", "inference"]
+    self.config = config
+    self.mode = mode
+    self.train_inception = train_inception
+
+    # Reader for the input data.
+    self.reader = tf.TFRecordReader()
+
+    # To match the "Show and Tell" paper we initialize all variables with a
+    # random uniform initializer.
+    self.initializer = tf.random_uniform_initializer(
+        minval=-self.config.initializer_scale,
+        maxval=self.config.initializer_scale)
+
+    # A float32 Tensor with shape [batch_size, height, width, channels].
+    self.images = None
+
+    # An int32 Tensor with shape [batch_size, padded_length].
+    self.input_seqs = None
+
+    # An int32 Tensor with shape [batch_size, padded_length].
+    self.target_seqs = None
+
+    # An int32 0/1 Tensor with shape [batch_size, padded_length].
+    self.input_mask = None
+
+    # A float32 Tensor with shape [batch_size, embedding_size].
+    self.image_embeddings = None
+
+    # A float32 Tensor with shape [batch_size, padded_length, embedding_size].
+    self.seq_embeddings = None
+
+    # A float32 scalar Tensor; the total loss for the trainer to optimize.
+    self.total_loss = None
+
+    # A float32 Tensor with shape [batch_size * padded_length].
+    self.target_cross_entropy_losses = None
+
+    # A float32 Tensor with shape [batch_size * padded_length].
+    self.target_cross_entropy_loss_weights = None
+
+    # Collection of variables from the inception submodel.
+    self.inception_variables = []
+
+    # Function to restore the inception submodel from checkpoint.
+    self.init_fn = None
+
+    # Global step Tensor.
+    self.global_step = None
+
+  def is_training(self):
+    """Returns true if the model is built for training mode."""
+    return self.mode == "train"
+
+  def process_image(self, encoded_image, thread_id=0):
+    """Decodes and processes an image string.
+
+    Args:
+      encoded_image: A scalar string Tensor; the encoded image.
+      thread_id: Preprocessing thread id used to select the ordering of color
+        distortions.
+
+    Returns:
+      A float32 Tensor of shape [height, width, 3]; the processed image.
+    """
+    return image_processing.process_image(encoded_image,
+                                          is_training=self.is_training(),
+                                          height=self.config.image_height,
+                                          width=self.config.image_width,
+                                          thread_id=thread_id,
+                                          image_format=self.config.image_format)
+
+  def build_inputs(self):
+    """Input prefetching, preprocessing and batching.
+
+    Outputs:
+      self.images
+      self.input_seqs
+      self.target_seqs (training and eval only)
+      self.input_mask (training and eval only)
+    """
+    if self.mode == "inference":
+      # In inference mode, images and inputs are fed via placeholders.
+      image_feed = tf.placeholder(dtype=tf.string, shape=[], name="image_feed")
+      input_feed = tf.placeholder(dtype=tf.int64,
+                                  shape=[None],  # batch_size
+                                  name="input_feed")
+
+      # Process image and insert batch dimensions.
+      images = tf.expand_dims(self.process_image(image_feed), 0)
+      input_seqs = tf.expand_dims(input_feed, 1)
+
+      # No target sequences or input mask in inference mode.
+      target_seqs = None
+      input_mask = None
+    else:
+      # Prefetch serialized SequenceExample protos.
+      input_queue = input_ops.prefetch_input_data(
+          self.reader,
+          self.config.input_file_pattern,
+          is_training=self.is_training(),
+          batch_size=self.config.batch_size,
+          values_per_shard=self.config.values_per_input_shard,
+          input_queue_capacity_factor=self.config.input_queue_capacity_factor,
+          num_reader_threads=self.config.num_input_reader_threads)
+
+      # Image processing and random distortion. Split across multiple threads
+      # with each thread applying a slightly different distortion.
+      assert self.config.num_preprocess_threads % 2 == 0
+      images_and_captions = []
+      for thread_id in range(self.config.num_preprocess_threads):
+        serialized_sequence_example = input_queue.dequeue()
+        encoded_image, caption = input_ops.parse_sequence_example(
+            serialized_sequence_example,
+            image_feature=self.config.image_feature_name,
+            caption_feature=self.config.caption_feature_name)
+        image = self.process_image(encoded_image, thread_id=thread_id)
+        images_and_captions.append([image, caption])
+
+      # Batch inputs.
+      queue_capacity = (2 * self.config.num_preprocess_threads *
+                        self.config.batch_size)
+      images, input_seqs, target_seqs, input_mask = (
+          input_ops.batch_with_dynamic_pad(images_and_captions,
+                                           batch_size=self.config.batch_size,
+                                           queue_capacity=queue_capacity))
+
+    self.images = images
+    self.input_seqs = input_seqs
+    self.target_seqs = target_seqs
+    self.input_mask = input_mask
+
+  def build_image_embeddings(self):
+    """Builds the image model subgraph and generates image embeddings.
+
+    Inputs:
+      self.images
+
+    Outputs:
+      self.image_embeddings
+    """
+    inception_output = image_embedding.inception_v3(
+        self.images,
+        trainable=self.train_inception,
+        is_training=self.is_training())
+    self.inception_variables = tf.get_collection(
+        tf.GraphKeys.VARIABLES, scope="InceptionV3")
+
+    # Map inception output into embedding space.
+    with tf.variable_scope("image_embedding") as scope:
+      image_embeddings = tf.contrib.layers.fully_connected(
+          inputs=inception_output,
+          num_outputs=self.config.embedding_size,
+          activation_fn=None,
+          weights_initializer=self.initializer,
+          biases_initializer=None,
+          scope=scope)
+
+    # Save the embedding size in the graph.
+    tf.constant(self.config.embedding_size, name="embedding_size")
+
+    self.image_embeddings = image_embeddings
+
+  def build_seq_embeddings(self):
+    """Builds the input sequence embeddings.
+
+    Inputs:
+      self.input_seqs
+
+    Outputs:
+      self.seq_embeddings
+    """
+    with tf.variable_scope("seq_embedding"), tf.device("/cpu:0"):
+      embedding_map = tf.get_variable(
+          name="map",
+          shape=[self.config.vocab_size, self.config.embedding_size],
+          initializer=self.initializer)
+      seq_embeddings = tf.nn.embedding_lookup(embedding_map, self.input_seqs)
+
+    self.seq_embeddings = seq_embeddings
+
+  def build_model(self):
+    """Builds the model.
+
+    Inputs:
+      self.image_embeddings
+      self.seq_embeddings
+      self.target_seqs (training and eval only)
+      self.input_mask (training and eval only)
+
+    Outputs:
+      self.total_loss (training and eval only)
+      self.target_cross_entropy_losses (training and eval only)
+      self.target_cross_entropy_loss_weights (training and eval only)
+    """
+    # This LSTM cell has biases and outputs tanh(new_c) * sigmoid(o), but the
+    # modified LSTM in the "Show and Tell" paper has no biases and outputs
+    # new_c * sigmoid(o).
+    lstm_cell = tf.nn.rnn_cell.BasicLSTMCell(
+        num_units=self.config.num_lstm_units, state_is_tuple=True)
+    if self.mode == "train":
+      lstm_cell = tf.nn.rnn_cell.DropoutWrapper(
+          lstm_cell,
+          input_keep_prob=self.config.lstm_dropout_keep_prob,
+          output_keep_prob=self.config.lstm_dropout_keep_prob)
+
+    with tf.variable_scope("lstm", initializer=self.initializer) as lstm_scope:
+      # Feed the image embeddings to set the initial LSTM state.
+      zero_state = lstm_cell.zero_state(
+          batch_size=self.image_embeddings.get_shape()[0], dtype=tf.float32)
+      _, initial_state = lstm_cell(self.image_embeddings, zero_state)
+
+      # Allow the LSTM variables to be reused.
+      lstm_scope.reuse_variables()
+
+      if self.mode == "inference":
+        # In inference mode, use concatenated states for convenient feeding and
+        # fetching.
+        tf.concat(1, initial_state, name="initial_state")
+
+        # Placeholder for feeding a batch of concatenated states.
+        state_feed = tf.placeholder(dtype=tf.float32,
+                                    shape=[None, sum(lstm_cell.state_size)],
+                                    name="state_feed")
+        state_tuple = tf.split(1, 2, state_feed)
+
+        # Run a single LSTM step.
+        lstm_outputs, state_tuple = lstm_cell(
+            inputs=tf.squeeze(self.seq_embeddings, squeeze_dims=[1]),
+            state=state_tuple)
+
+        # Concatentate the resulting state.
+        tf.concat(1, state_tuple, name="state")
+      else:
+        # Run the batch of sequence embeddings through the LSTM.
+        sequence_length = tf.reduce_sum(self.input_mask, 1)
+        lstm_outputs, _ = tf.nn.dynamic_rnn(cell=lstm_cell,
+                                            inputs=self.seq_embeddings,
+                                            sequence_length=sequence_length,
+                                            initial_state=initial_state,
+                                            dtype=tf.float32,
+                                            scope=lstm_scope)
+
+    # Stack batches vertically.
+    lstm_outputs = tf.reshape(lstm_outputs, [-1, lstm_cell.output_size])
+
+    with tf.variable_scope("logits") as logits_scope:
+      logits = tf.contrib.layers.fully_connected(
+          inputs=lstm_outputs,
+          num_outputs=self.config.vocab_size,
+          activation_fn=None,
+          weights_initializer=self.initializer,
+          scope=logits_scope)
+
+    if self.mode == "inference":
+      tf.nn.softmax(logits, name="softmax")
+    else:
+      targets = tf.reshape(self.target_seqs, [-1])
+      weights = tf.to_float(tf.reshape(self.input_mask, [-1]))
+
+      # Compute losses.
+      losses = tf.nn.sparse_softmax_cross_entropy_with_logits(logits, targets)
+      batch_loss = tf.div(tf.reduce_sum(tf.mul(losses, weights)),
+                          tf.reduce_sum(weights),
+                          name="batch_loss")
+      tf.contrib.losses.add_loss(batch_loss)
+      total_loss = tf.contrib.losses.get_total_loss()
+
+      # Add summaries.
+      tf.scalar_summary("batch_loss", batch_loss)
+      tf.scalar_summary("total_loss", total_loss)
+      for var in tf.trainable_variables():
+        tf.histogram_summary(var.op.name, var)
+
+      self.total_loss = total_loss
+      self.target_cross_entropy_losses = losses  # Used in evaluation.
+      self.target_cross_entropy_loss_weights = weights  # Used in evaluation.
+
+  def setup_inception_initializer(self):
+    """Sets up the function to restore inception variables from checkpoint."""
+    if self.mode != "inference":
+      # Restore inception variables only.
+      saver = tf.train.Saver(self.inception_variables)
+
+      def restore_fn(sess):
+        tf.logging.info("Restoring Inception variables from checkpoint file %s",
+                        self.config.inception_checkpoint_file)
+        saver.restore(sess, self.config.inception_checkpoint_file)
+
+      self.init_fn = restore_fn
+
+  def setup_global_step(self):
+    """Sets up the global step Tensor."""
+    global_step = tf.Variable(
+        initial_value=0,
+        name="global_step",
+        trainable=False,
+        collections=[tf.GraphKeys.GLOBAL_STEP, tf.GraphKeys.VARIABLES])
+
+    self.global_step = global_step
+
+  def setup_saver(self):
+    """Sets up the Saver for loading and saving model checkpoints."""
+    self.saver = tf.train.Saver(
+        max_to_keep=self.config.max_checkpoints_to_keep,
+        keep_checkpoint_every_n_hours=self.config.keep_checkpoint_every_n_hours)
+
+  def build(self):
+    """Creates all ops for training and evaluation."""
+    self.build_inputs()
+    self.build_image_embeddings()
+    self.build_seq_embeddings()
+    self.build_model()
+    self.setup_inception_initializer()
+    self.setup_global_step()
+    self.setup_saver()

im2txt/im2txt/show_and_tell_model_test.py

+# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+"""Tests for tensorflow_models.im2txt.show_and_tell_model."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+
+import numpy as np
+import tensorflow as tf
+
+from im2txt import configuration
+from im2txt import show_and_tell_model
+
+
+class ShowAndTellModel(show_and_tell_model.ShowAndTellModel):
+  """Subclass of ShowAndTellModel without the disk I/O."""
+
+  def build_inputs(self):
+    if self.mode == "inference":
+      # Inference mode doesn't read from disk, so defer to parent.
+      return super(ShowAndTellModel, self).build_inputs()
+    else:
+      # Replace disk I/O with random Tensors.
+      self.images = tf.random_uniform(
+          shape=[self.config.batch_size, self.config.image_height,
+                 self.config.image_width, 3],
+          minval=-1,
+          maxval=1)
+      self.input_seqs = tf.random_uniform(
+          [self.config.batch_size, 15],
+          minval=0,
+          maxval=self.config.vocab_size,
+          dtype=tf.int64)
+      self.target_seqs = tf.random_uniform(
+          [self.config.batch_size, 15],
+          minval=0,
+          maxval=self.config.vocab_size,
+          dtype=tf.int64)
+      self.input_mask = tf.ones_like(self.input_seqs)
+
+
+class ShowAndTellModelTest(tf.test.TestCase):
+
+  def setUp(self):
+    super(ShowAndTellModelTest, self).setUp()
+    self._model_config = configuration.ModelConfig()
+
+  def _countModelParameters(self):
+    """Counts the number of parameters in the model at top level scope."""
+    counter = {}
+    for v in tf.all_variables():
+      name = v.op.name.split("/")[0]
+      num_params = v.get_shape().num_elements()
+      assert num_params
+      counter[name] = counter.get(name, 0) + num_params
+    return counter
+
+  def _checkModelParameters(self):
+    """Verifies the number of parameters in the model."""
+    param_counts = self._countModelParameters()
+    expected_param_counts = {
+        "InceptionV3": 21802784,
+        # inception_output_size * embedding_size
+        "image_embedding": 1048576,
+        # vocab_size * embedding_size
+        "seq_embedding": 6144000,
+        # (embedding_size + num_lstm_units + 1) * 4 * num_lstm_units
+        "lstm": 2099200,
+        # (num_lstm_units + 1) * vocab_size
+        "logits": 6156000,
+        "global_step": 1,
+    }
+    self.assertDictEqual(expected_param_counts, param_counts)
+
+  def _checkOutputs(self, expected_shapes, feed_dict=None):
+    """Verifies that the model produces expected outputs.
+
+    Args:
+      expected_shapes: A dict mapping Tensor or Tensor name to expected output
+        shape.
+      feed_dict: Values of Tensors to feed into Session.run().
+    """
+    fetches = expected_shapes.keys()
+
+    with self.test_session() as sess:
+      sess.run(tf.initialize_all_variables())
+      outputs = sess.run(fetches, feed_dict)
+
+    for index, output in enumerate(outputs):
+      tensor = fetches[index]
+      expected = expected_shapes[tensor]
+      actual = output.shape
+      if expected != actual:
+        self.fail("Tensor %s has shape %s (expected %s)." %
+                  (tensor, actual, expected))
+
+  def testBuildForTraining(self):
+    model = ShowAndTellModel(self._model_config, mode="train")
+    model.build()
+
+    self._checkModelParameters()
+
+    expected_shapes = {
+        # [batch_size, image_height, image_width, 3]
+        model.images: (32, 299, 299, 3),
+        # [batch_size, sequence_length]
+        model.input_seqs: (32, 15),
+        # [batch_size, sequence_length]
+        model.target_seqs: (32, 15),
+        # [batch_size, sequence_length]
+        model.input_mask: (32, 15),
+        # [batch_size, embedding_size]
+        model.image_embeddings: (32, 512),
+        # [batch_size, sequence_length, embedding_size]
+        model.seq_embeddings: (32, 15, 512),
+        # Scalar
+        model.total_loss: (),
+        # [batch_size * sequence_length]
+        model.target_cross_entropy_losses: (480,),
+        # [batch_size * sequence_length]
+        model.target_cross_entropy_loss_weights: (480,),
+    }
+    self._checkOutputs(expected_shapes)
+
+  def testBuildForEval(self):
+    model = ShowAndTellModel(self._model_config, mode="eval")
+    model.build()
+
+    self._checkModelParameters()
+
+    expected_shapes = {
+        # [batch_size, image_height, image_width, 3]
+        model.images: (32, 299, 299, 3),
+        # [batch_size, sequence_length]
+        model.input_seqs: (32, 15),
+        # [batch_size, sequence_length]
+        model.target_seqs: (32, 15),
+        # [batch_size, sequence_length]
+        model.input_mask: (32, 15),
+        # [batch_size, embedding_size]
+        model.image_embeddings: (32, 512),
+        # [batch_size, sequence_length, embedding_size]
+        model.seq_embeddings: (32, 15, 512),
+        # Scalar
+        model.total_loss: (),
+        # [batch_size * sequence_length]
+        model.target_cross_entropy_losses: (480,),
+        # [batch_size * sequence_length]
+        model.target_cross_entropy_loss_weights: (480,),
+    }
+    self._checkOutputs(expected_shapes)
+
+  def testBuildForInference(self):
+    model = ShowAndTellModel(self._model_config, mode="inference")
+    model.build()
+
+    self._checkModelParameters()
+
+    # Test feeding an image to get the initial LSTM state.
+    images_feed = np.random.rand(1, 299, 299, 3)
+    feed_dict = {model.images: images_feed}
+    expected_shapes = {
+        # [batch_size, embedding_size]
+        model.image_embeddings: (1, 512),
+        # [batch_size, 2 * num_lstm_units]
+        "lstm/initial_state:0": (1, 1024),
+    }
+    self._checkOutputs(expected_shapes, feed_dict)
+
+    # Test feeding a batch of inputs and LSTM states to get softmax output and
+    # LSTM states.
+    input_feed = np.random.randint(0, 10, size=3)
+    state_feed = np.random.rand(3, 1024)
+    feed_dict = {"input_feed:0": input_feed, "lstm/state_feed:0": state_feed}
+    expected_shapes = {
+        # [batch_size, 2 * num_lstm_units]
+        "lstm/state:0": (3, 1024),
+        # [batch_size, vocab_size]
+        "softmax:0": (3, 12000),
+    }
+    self._checkOutputs(expected_shapes, feed_dict)
+
+
+if __name__ == "__main__":
+  tf.test.main()

im2txt/im2txt/train.py

+# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+"""Train the model."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+
+import tensorflow as tf
+
+from im2txt import configuration
+from im2txt import show_and_tell_model
+
+FLAGS = tf.app.flags.FLAGS
+
+tf.flags.DEFINE_string("input_file_pattern", "",
+                       "File pattern of sharded TFRecord input files.")
+tf.flags.DEFINE_string("inception_checkpoint_file", "",
+                       "Path to a pretrained inception_v3 model.")
+tf.flags.DEFINE_string("train_dir", "",
+                       "Directory for saving and loading model checkpoints.")
+tf.flags.DEFINE_boolean("train_inception", False,
+                        "Whether to train inception submodel variables.")
+tf.flags.DEFINE_integer("number_of_steps", 1000000, "Number of training steps.")
+tf.flags.DEFINE_integer("log_every_n_steps", 1,
+                        "Frequency at which loss and global step are logged.")
+
+tf.logging.set_verbosity(tf.logging.INFO)
+
+
+def main(unused_argv):
+  assert FLAGS.input_file_pattern, "--input_file_pattern is required"
+  assert FLAGS.train_dir, "--train_dir is required"
+
+  model_config = configuration.ModelConfig()
+  model_config.input_file_pattern = FLAGS.input_file_pattern
+  model_config.inception_checkpoint_file = FLAGS.inception_checkpoint_file
+  training_config = configuration.TrainingConfig()
+
+  # Create training directory.
+  train_dir = FLAGS.train_dir
+  if not tf.gfile.IsDirectory(train_dir):
+    tf.logging.info("Creating training directory: %s", train_dir)
+    tf.gfile.MakeDirs(train_dir)
+
+  # Build the TensorFlow graph.
+  g = tf.Graph()
+  with g.as_default():
+    # Build the model.
+    model = show_and_tell_model.ShowAndTellModel(
+        model_config, mode="train", train_inception=FLAGS.train_inception)
+    model.build()
+
+    # Set up the learning rate.
+    learning_rate_decay_fn = None
+    if FLAGS.train_inception:
+      learning_rate = tf.constant(training_config.train_inception_learning_rate)
+    else:
+      learning_rate = tf.constant(training_config.initial_learning_rate)
+      if training_config.learning_rate_decay_factor > 0:
+        num_batches_per_epoch = (training_config.num_examples_per_epoch /
+                                 model_config.batch_size)
+        decay_steps = int(num_batches_per_epoch *
+                          training_config.num_epochs_per_decay)
+
+        def _learning_rate_decay_fn(learning_rate, global_step):
+          return tf.train.exponential_decay(
+              learning_rate,
+              global_step,
+              decay_steps=decay_steps,
+              decay_rate=training_config.learning_rate_decay_factor,
+              staircase=True)
+
+        learning_rate_decay_fn = _learning_rate_decay_fn
+
+    # Set up the training ops.
+    train_op = tf.contrib.layers.optimize_loss(
+        loss=model.total_loss,
+        global_step=model.global_step,
+        learning_rate=learning_rate,
+        optimizer=training_config.optimizer,
+        clip_gradients=training_config.clip_gradients,
+        learning_rate_decay_fn=learning_rate_decay_fn)
+
+  # Run training.
+  tf.contrib.slim.learning.train(
+      train_op,
+      train_dir,
+      log_every_n_steps=FLAGS.log_every_n_steps,
+      graph=g,
+      global_step=model.global_step,
+      number_of_steps=FLAGS.number_of_steps,
+      init_fn=model.init_fn,
+      saver=model.saver)
+
+
+if __name__ == "__main__":
+  tf.app.run()