Add support for databases which contain more than one sample in one file

bob/learn/tensorflow/script/db_to_tfrecords.py

@@ -69,6 +69,10 @@ The config files should have the following objects totally:
   # Shuffle the files before writing them into a tfrecords. [default: False]
   shuffle = True
 
+  # Whether the each file contains one sample or more. [default: True] If
+  # this is False, the loaded samples from a file are iterated over and each
+  # of them is saved as an independent feature.
+  one_file_one_sample = True
 """
 
 from __future__ import absolute_import
@@ -81,7 +85,6 @@ from bob.io.base import create_directories_safe
 from bob.bio.base.utils import load, read_config_file
 from bob.core.log import setup, set_verbosity_level
 logger = setup(__name__)
-import numpy
 
 
 def _bytes_feature(value):
@@ -92,73 +95,63 @@ def _int64_feature(value):
     return tf.train.Feature(int64_list=tf.train.Int64List(value=[value]))
 
 
-def bob2skimage(bob_image):
-    """
-    Convert bob color image to the skcit image
-    """
-    
-    if bob_image.ndim==2:
-        skimage = numpy.zeros(shape=(bob_image.shape[0], bob_image.shape[1], 1))
-        skimage[:, :, 0] = bob_image
-    else:
-        skimage = numpy.zeros(shape=(bob_image.shape[1], bob_image.shape[2], bob_image.shape[0]))
-        skimage[:, :, 2] = bob_image[0, :, :]
-        skimage[:, :, 1] = bob_image[1, :, :]    
-        skimage[:, :, 0] = bob_image[2, :, :]
+def write_a_sample(writer, data, label):
+    feature = {'train/data': _bytes_feature(data.astype('float32').tostring()),
+               'train/label': _int64_feature(label)}
+
+    example = tf.train.Example(features=tf.train.Features(feature=feature))
+    writer.write(example.SerializeToString())
 
-    return skimage
 
 def main(argv=None):
-  from docopt import docopt
-  import os
-  import sys
-  import pkg_resources
-  docs = __doc__ % {'prog': os.path.basename(sys.argv[0])}
-  version = pkg_resources.require('bob.learn.tensorflow')[0].version
-  args = docopt(docs, argv=argv, version=version)
-  config_files = args['<config_files>']
-  config = read_config_file(config_files)
-
-  # Sets-up logging
-  verbosity = getattr(config, 'verbose', 0)
-  set_verbosity_level(logger, verbosity)
-
-  database = config.database
-  data_dir, output_dir = config.data_dir, config.output_dir
-  file_to_label = config.file_to_label
-
-  reader = getattr(config, 'reader', load)
-  groups = getattr(config, 'groups', ['world'])
-  data_extension = getattr(config, 'data_extension', '.hdf5')
-  shuffle = getattr(config, 'shuffle', False)
-  
-  data_type = getattr(config, 'data_type', "float32")
-
-  create_directories_safe(output_dir)
-  if not isinstance(groups, (list, tuple)):
-    groups = [groups]
-
-  for group in groups:
-    output_file = os.path.join(output_dir, '{}.tfrecords'.format(group))
-    files = database.all_files(groups=group)
-    if shuffle:
-      random.shuffle(files)
-    n_files = len(files)
-    with tf.python_io.TFRecordWriter(output_file) as writer:
-      for i, f in enumerate(files):
-        logger.info('Processing file %d out of %d', i + 1, n_files)
-
-        path = f.make_path(data_dir, data_extension)
-        img = bob2skimage(reader(path)).astype(data_type)
-        img = img.reshape((list(img.shape) + [1]))
-        data = img.tostring()
-
-        feature = {'train/data': _bytes_feature(data),
-                   'train/label': _int64_feature(file_to_label(f))}
-
-        example = tf.train.Example(features=tf.train.Features(feature=feature))
-        writer.write(example.SerializeToString())
+    from docopt import docopt
+    import os
+    import sys
+    import pkg_resources
+    docs = __doc__ % {'prog': os.path.basename(sys.argv[0])}
+    version = pkg_resources.require('bob.learn.tensorflow')[0].version
+    args = docopt(docs, argv=argv, version=version)
+    config_files = args['<config_files>']
+    config = read_config_file(config_files)
+
+    # Sets-up logging
+    verbosity = getattr(config, 'verbose', 0)
+    set_verbosity_level(logger, verbosity)
+
+    database = config.database
+    data_dir, output_dir = config.data_dir, config.output_dir
+    file_to_label = config.file_to_label
+
+    reader = getattr(config, 'reader', load)
+    groups = getattr(config, 'groups', ['world'])
+    data_extension = getattr(config, 'data_extension', '.hdf5')
+    shuffle = getattr(config, 'shuffle', False)
+    one_file_one_sample = getattr(config, 'one_file_one_sample', True)
+
+    create_directories_safe(output_dir)
+    if not isinstance(groups, (list, tuple)):
+        groups = [groups]
+
+    for group in groups:
+        output_file = os.path.join(output_dir, '{}.tfrecords'.format(group))
+        files = database.all_files(groups=group)
+        if shuffle:
+            random.shuffle(files)
+        n_files = len(files)
+        with tf.python_io.TFRecordWriter(output_file) as writer:
+            for i, f in enumerate(files):
+                logger.info('Processing file %d out of %d', i + 1, n_files)
+
+                path = f.make_path(data_dir, data_extension)
+                data = reader(path)
+                label = file_to_label(f)
+
+                if one_file_one_sample:
+                    write_a_sample(writer, data, label)
+                else:
+                    for sample in data:
+                        write_a_sample(writer, sample, label)
 
 
 if __name__ == '__main__':
-  main()
+    main()