If you are interested in how to input your own data in TensorFlow, you can look at this tutorial.
I've also written a guide with best practices for CS230 at Stanford here.
New answer (with tf.data
) and with labels
With the introduction of tf.data
in r1.4
, we can create a batch of images without placeholders and without queues. The steps are the following:
- Create a list containing the filenames of the images and a corresponding list of labels
- Create a
tf.data.Dataset
reading these filenames and labels
- Preprocess the data
- Create an iterator from the
tf.data.Dataset
which will yield the next batch
The code is:
# step 1
filenames = tf.constant(['im_01.jpg', 'im_02.jpg', 'im_03.jpg', 'im_04.jpg'])
labels = tf.constant([0, 1, 0, 1])
# step 2: create a dataset returning slices of `filenames`
dataset = tf.data.Dataset.from_tensor_slices((filenames, labels))
# step 3: parse every image in the dataset using `map`
def _parse_function(filename, label):
image_string = tf.read_file(filename)
image_decoded = tf.image.decode_jpeg(image_string, channels=3)
image = tf.cast(image_decoded, tf.float32)
return image, label
dataset = dataset.map(_parse_function)
dataset = dataset.batch(2)
# step 4: create iterator and final input tensor
iterator = dataset.make_one_shot_iterator()
images, labels = iterator.get_next()
Now we can run directly sess.run([images, labels])
without feeding any data through placeholders.
Old answer (with TensorFlow queues)
To sum it up you have multiple steps:
- Create a list of filenames (ex: the paths to your images)
- Create a TensorFlow filename queue
- Read and decode each image, resize them to a fixed size (necessary for batching)
- Output a batch of these images
The simplest code would be:
# step 1
filenames = ['im_01.jpg', 'im_02.jpg', 'im_03.jpg', 'im_04.jpg']
# step 2
filename_queue = tf.train.string_input_producer(filenames)
# step 3: read, decode and resize images
reader = tf.WholeFileReader()
filename, content = reader.read(filename_queue)
image = tf.image.decode_jpeg(content, channels=3)
image = tf.cast(image, tf.float32)
resized_image = tf.image.resize_images(image, [224, 224])
# step 4: Batching
image_batch = tf.train.batch([resized_image], batch_size=8)
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