Tensorflow: Read CSV - tensorflow

filename_queue = tf.train.string_input_producer([csv_file_path], shuffle=False)
reader = tf.TextLineReader()
_, serialized_example = reader.read(filename_queue)
filename = tf.decode_csv(serialized_example, record_defaults=[[""]], field_delim=',')
# Input
png = tf.read_file(filename)
I am reading from a CSV file with one Column.
I am getting the following error.
ValueError: **Shape** must be rank 0 but is rank 1 for 'ReadFile' (op: 'ReadFile') with input shapes: [1].
Could someone tell me the issue?

tf.read_file() needs a scalar input (i.e., just one string), but the results of tf.decode_csv are coming back in a "rank 1" context, i.e., a 1-D list. You need to dereference the results:
filename = tf.decode_csv(serialized_example, record_defaults=[[""]], field_delim=',')
filename = filename[0] # <-- add this.
png = tf.read_file(filename)
For more detail, see the docs for tf.decode_csv -- note that the return type is a list of Tensor objects.

Related

Decode JPEG from tfrecords error: ValueError: Shape must be rank 0 but is rank 1 for 'DecodeJpeg' (op: 'DecodeJpeg') with input shapes: [?]

I applied the method in this github to write JPEG files into .tfrecords. But I have issues when parsing them.
Here's my code for writing the tfrecords, each x_img is a numpy array, and each x_img[i] contains fixed amount of img_bytes
img_bytes = open(join(frames_path, vid, img_list[current]),'rb').read()
...
"x_img": tf.train.Feature( bytes_list = tf.train.BytesList( value= x_img[i])),
When parsing, I did this:
def parse_func(example_proto):
# FEATURES
feature_description = {
"x_img": tf.io.VarLenFeature(tf.string),
}
feat = tf.io.parse_single_example(example_proto, feature_description)
x = {}
x_img = tf.sparse.to_dense(feat["x_img"])
x_img = tf.io.decode_jpeg(x_img, channels = 3)
x["x_img"] = x_img/255
return x
But it returns error:
ValueError: Shape must be rank 0 but is rank 1 for 'DecodeJpeg' (op: 'DecodeJpeg') with input shapes: [?].
What is the right way to decode a JPEG which was previously stored in bytes?
Full answer:
tf.io.decode_jpeg works fine. The reason I got the error is that I shaped the input as (n, width, height, 3). But the function decode_jpeg only works on a single image instead of n images.
By writing:
x_img = tf.stack([
tf.io.decode_jpeg(x_images[0], channels = 3),
tf.io.decode_jpeg(x_images[1], channels = 3),
tf.io.decode_jpeg(x_images[2], channels = 3),
])
I could recover the bytes to JPEG. The more efficient way is using list comprehension, but unfortunately, list comprehension is not supported now (see here).
The reason for writing bytes into .tfrecords instead of using plt.imread() or cv2.imread() is that it doesn't decompress the image, so the process would be much faster and space-efficient. I didn't calculate it precisely, but decompressing JPEG images leads ~6x increase in disk space.

preprocess images with tf.data.experimental.make_csv_dataset or with read_csv option

I am adding this summarization of my issue to make it easier to understand:
I want to do exactly what is done in the following tensorflow example:
https://www.tensorflow.org/guide/datasets
# Reads an image from a file, decodes it into a dense tensor, and resizes it
# to a fixed shape.
def _parse_function(filename, label):
image_string = tf.read_file(filename)
image_decoded = tf.image.decode_jpeg(image_string)
image_resized = tf.image.resize_images(image_decoded, [28, 28])
return image_resized, label
# A vector of filenames.
filenames = tf.constant(["/var/data/image1.jpg", "/var/data/image2.jpg", ...])
# `labels[i]` is the label for the image in `filenames[i].
labels = tf.constant([0, 37, ...])
dataset = tf.data.Dataset.from_tensor_slices((filenames, labels))
dataset = dataset.map(_parse_function)
The only differences are: I read the data from CSV that has many more features and then I call the map method:
dataset = tf.data.experimental.make_csv_dataset(file_pattern=CSV_PATH_TRAIN,
batch_size=2,
header=True,
label_name = 'label').map(_parse_function)
How does my _parse_function need to look like? How do I access the image path features, updates it to be an image presentation and return a modified numeric matrix feature of the image without changing anything at the other features?
thanks,
eilalan
==================Here are my code tries:==================
My code reads a CSV with feature columns and label. One of the features is image path, the others are strings.
The image path need to be processed into image numbers matrix.
I have tried doing so with the following options. In both ways tf.read_file fails with the input dimension error.
My question is how to pass one image at a time into the map methods
def read_image_png_option_1(image_path, depth=3, scale=False):
"""Reads the image from image_path (tf.string tensor) [jpg image].
Cast the result to float32 and if scale=True scale it in [-1,1]
using scale_image. Otherwise the values are in [0,1]
Reuturn:
the decoded jpeg image, casted to float32
"""
image = tf.image.convert_image_dtype(
tf.image.decode_png(tf.read_file(image_path), channels=depth),
dtype=tf.float32)
if scale:
image = scale_image(image)
return image
def read_image_png_option_2(features, depth=3, scale=False):
"""Reads the image from image_path (tf.string tensor) [jpg image].
Cast the result to float32 and if scale=True scale it in [-1,1]
using scale_image. Otherwise the values are in [0,1]
Reuturn:
the decoded jpeg image, casted to float32
"""
image = tf.image.convert_image_dtype(
tf.image.decode_png(tf.read_file(features['image']), channels=depth),
dtype=tf.float32)
if scale:
image = scale_image(image)
features['image'] = image
return features
def make_input_fn(fileName,batch_size=8, perform_shuffle=True):
"""An input function for training """
def _input_fn():
def decode_csv(line):
print('line is ',line)
filename_col,label_col,gender_col,ethinicity = tf.decode_csv(line,
[[""]]*amount_of_columns_csv,
field_delim=",",
na_value='NA',
select_cols=None)
image_col = read_image_png_option_1(filename_col)
d = dict(zip(['image','label','gender','ethinicity'], [image_col,label_col,gender_col,ethinicity])), label
return d
## OPTION 1:
# filenames could be more than one
# dataset = tf.data.TextLineDataset(filenames=fileName).skip(1).batch(batch_size).map(decode_csv)
## OPTION 2:
dataset = tf.data.experimental.make_csv_dataset(file_pattern=CSV_PATH_TRAIN,
batch_size=2,
header=True,
label_name = 'label').map(read_image_png_option_2)
#select_columns=[0,1]) #[tf.string,tf.string,tf.string,tf.string])
if perform_shuffle:
dataset = dataset.shuffle(buffer_size=256)
return dataset
return _input_fn()
train_input_fn = lambda: make_input_fn(CSV_PATH_TRAIN)
train_spec = tf.estimator.TrainSpec(input_fn=train_input_fn, max_steps=50)
eval_input_fn = lambda: make_input_fn(CSV_PATH_VAL)
eval_spec = tf.estimator.EvalSpec(eval_input_fn)
feature_columns = [tf.feature_column.numeric_column("image",shape=(224,224)), # here i need a pyhton method to transform
tf.feature_column.categorical_column_with_vocabulary_list("gender", ["ww","ee"]),
tf.feature_column.categorical_column_with_vocabulary_list("ethinicity",["xx","yy"])]
estimator = tf.estimator.DNNClassifier(feature_columns=feature_columns,hidden_units=[1024, 512, 256],warm_start_from=ws)
tf.estimator.train_and_evaluate(estimator, train_spec=train_spec, eval_spec=eval_spec)
Error for option 2:
ValueError: Shape must be rank 0 but is rank 1 for 'ReadFile' (op: 'ReadFile') with input shapes: [2].
Error for option 1:
ValueError: Shape must be rank 0 but is rank 1 for 'ReadFile' (op: 'ReadFile') with input shapes: [?].
Any help is appreciated.
Thanks
First you need to read the CSV file into dataset.
Then for each row in your CSV you can call your parse function.
def getInput(fileList):
# returns a dataset containing list of filenames
files = tf.data.Dataset.from_tensor_slices(fileList)
# Returs a dataset containing list of rows taken from all the files in file list.
# dataset is filled dynamically and not all entries are read at once
dataset = files.interleave(tf.data.TextLineDataset)
# call parse function for each row
# returned dataset will contain list of whatever the parse function is returning for the row
# we want the image path to be converted to decoded image in parse function
dataset = dataset.map(_parse_function, num_parallel_calls=8)
# return an iterator for the dataset which will be used to get elements.
return dataset.make_one_shot_iterator().get_next()
The parse function will be passed only one parameter that will be a single row from the CSV file. You need to decode the CSV and do further processing on each value.
Let's say you have 3 columns in your CSV each being a string.
def _parse_function(value):
columns_default = [[""], [""], [""]]
# this will be a tensor of columns in the row
columns = tf.decode_csv(value, record_defaults=columns_default,
field_delim=',')
col_names = ["label", "imagepath", "c3"]
features = dict(zip(col_names, columns))
for f, tensor in features.items():
# process imagepath to decoded image
if f == "imagepath":
image_string = tf.read_file(tensor)
image_decoded = tf.image.decode_jpeg(image_string)
image_resized = tf.image.resize_images(image_decoded, [28, 28])
features[f] = image_resized
labels = tf.equal(features.pop('label'), "1")
labels = tf.expand_dims(labels, 0)
return features, labels
Edit:
Explanation for comment:
Dataset object simply contains a list of elements. The elements can be tensors or a tuple of tensors etc. Tensor object can contain anything. It could represent a single feature, a single record or a batch of record. Further dataset API provide handy methods to manipulate the elements within.
If you are using dataset with another API like estimator then they expect the dataset elements to be in specific format which is what need to return from our input function for eg.
https://www.tensorflow.org/api_docs/python/tf/estimator/Estimator#train
I have edited my code block above to describe what dataset object at each step will contain.
From what I understand is that you have image path as one of the field in your CSV and you want to convert that path into an actual decoded image which you will use as one of the feature.
Since the image is going to be just one of the feature, you should not try to create a dataset using image files alone. Dataset object will include all your features at once.
So doing this would be incorrect:
files = tf.data.Dataset.from_tensor_slices(ds['imagepath'])
dataset = files.interleave(tf.data.TextLineDataset)
If you are using make_csv() function to read your csv then it will convert each row of your csv into one record where one record will contain list of all features, same as columns of csv.
So each element in the returned dataset should contain a single tensor containing all your features.
Here your image path will be one of the features. now you want to transform that image path to decoded image.
I suppose you can do it by applying a parse function to elements of dataset using map() function but it will be slightly tricky as all your features are already packed inside a single tensor.

Why am I getting shape errors when trying to pass a batch from the Tensorflow Dataset API to my session operations?

I am dealing with an issue in my conversion over to the Dataset API and I guess I just don't have enough experience yet with the API to know how to handle the below situation. We currently have image augmentation that we perform currently using queueing and batching. I was tasked with checking out the new Dataset API and converting over our existing implementation using it rather than queues.
What we would like to do is get a reference to all the paths and handle all operations from just that reference. As you see in the dataset initialization, I have mapped the parse_fn to the dataset itself which then goes about reading the file and extracting the initial values from the filenames. However when I then go about calling the iterators next_batch method and then pass those values to get_summary, I'm now getting an error around shape. I have been trying a number of things which just keeps changing the error and so I felt I should see if anyone on SO saw possibly that I was going about this all wrong and should be taking a different route. Does anything jump out as absolutely wrong in my use of the Dataset API?
Should I not be calling the ops this way any longer? I noticed the majority of the examples I saw they would get the batch, pass the variables to the op and then capture that in a variable and pass that to sess.run, however I haven't found an easy way of doing that as of yet with our setup that wasn't erroring so this was the approach I took instead (but its still erroring). I'll be continuing to try to trace down the problem and post here should I find anything, but if anyone sees something please advise. Thanks!
Current Error:
... in get_summary summary, acc = sess.run([self._summary_op,
self._accuracy], feed_dict=feed_dict) ValueError: Cannot feed value of
shape (32,) for Tensor 'ph_input_labels:0', which has shape '(?, 1)
Below is the block where the get_summary method is called and error is fired:
def perform_train():
if __name__ == '__main__':
#Get all our image paths
filenames = data_layer_train.get_image_paths()
next_batch, iterator = preproc_image_fn(filenames=filenames)
with tf.Session(config=tf.ConfigProto(gpu_options=gpu_options)) as sess:
with sess.graph.as_default():
# Set the random seed for tensorflow
tf.set_random_seed(cfg.RNG_SEED)
classifier_network = c_common.create_model(len(products_to_class_dict), is_training=True)
optimizer, global_step_var = c_common.create_optimizer(classifier_network)
sess.run(tf.local_variables_initializer())
sess.run(tf.global_variables_initializer())
# Init tables and dataset iterator
sess.run(tf.tables_initializer())
sess.run(iterator.initializer)
cur_epoch = 0
blobs = None
try:
epoch_size = data_layer_train.get_steps_per_epoch()
num_steps = num_epochs * epoch_size
for step in range(num_steps):
timer_summary.tic()
if blobs is None:
#Now populate from our training dataset
blobs = sess.run(next_batch)
# *************** Below is where it is erroring *****************
summary_train, acc = classifier_network.get_summary(sess, blobs["images"], blobs["labels"], blobs["weights"])
...
Believe the error is in preproc_image_fn:
def preproc_image_fn(filenames, images=None, labels=None, image_paths=None, cells=None, weights=None):
def _parse_fn(filename, label, weight):
augment_instance = False
paths=[]
selected_cells=[]
if vals.FIRST_ITER:
#Perform our check of the path to see if _data_augmentation is within it
#If so set augment_instance to true and replace the substring with an empty string
new_filename = tf.regex_replace(filename, "_data_augmentation", "")
contains = tf.equal(tf.size(tf.string_split([filename], "")), tf.size(tf.string_split([new_filename])))
filename = new_filename
if contains is True:
augment_instance = True
core_file = tf.string_split([filename], '\\').values[-1]
product_id = tf.string_split([core_file], ".").values[0]
label = search_tf_table_for_entry(product_id)
weight = data_layer_train.get_weights(product_id)
image_string = tf.read_file(filename)
img = tf.image.decode_image(image_string, channels=data_layer_train._channels)
img.set_shape([None, None, None])
img = tf.image.resize_images(img, [data_layer_train._target_height, data_layer_train._target_width])
#Previously I was returning the below, but I was getting an error from the op when assigning feed_dict stating that it didnt like the dictionary
#retval = dict(zip([filename], [img])), label, weight
retval = img, label, weight
return retval
num_files = len(filenames)
filenames = tf.constant(filenames)
#*********** Setup dataset below ************
dataset = tf.data.Dataset.from_tensor_slices((filenames, labels, weights))
dataset=dataset.map(_parse_fn)
dataset = dataset.repeat()
dataset = dataset.batch(32)
iterator = dataset.make_initializable_iterator()
batch_features, batch_labels, batch_weights = iterator.get_next()
return {'images': batch_features, 'labels': batch_labels, 'weights': batch_weights}, iterator
def search_tf_table_for_entry(self, product_id):
'''Looks up keys in the table and outputs the values. Will return -1 if not found '''
if product_id is not None:
return self._products_to_class_table.lookup(product_id)
else:
if not self._real_eval:
logger().info("class not found in training {} ".format(product_id))
return -1
Where I create the model and have the placeholders used previously:
...
def create_model(self):
weights_regularizer = tf.contrib.layers.l2_regularizer(cfg.TRAIN.WEIGHT_DECAY)
biases_regularizer = weights_regularizer
# Input data.
self._input_images = tf.placeholder(
tf.float32, shape=(None, self._image_height, self._image_width, self._num_channels), name="ph_input_images")
self._input_labels = tf.placeholder(tf.int64, shape=(None, 1), name="ph_input_labels")
self._input_weights = tf.placeholder(tf.float32, shape=(None, 1), name="ph_input_weights")
self._is_training = tf.placeholder(tf.bool, name='ph_is_training')
self._keep_prob = tf.placeholder(tf.float32, name="ph_keep_prob")
self._accuracy = tf.reduce_mean(tf.cast(self._correct_prediction, tf.float32))
...
self.create_summaries()
def create_summaries(self):
val_summaries = []
with tf.device("/cpu:0"):
for var in self._act_summaries:
self._add_act_summary(var)
for var in self._train_summaries:
self._add_train_summary(var)
self._summary_op = tf.summary.merge_all()
self._summary_op_val = tf.summary.merge(val_summaries)
def get_summary(self, sess, images, labels, weights):
feed_dict = {self._input_images: images, self._input_labels: labels,
self._input_weights: weights, self._is_training: False}
summary, acc = sess.run([self._summary_op, self._accuracy], feed_dict=feed_dict)
return summary, acc
Since the error says:
Cannot feed value of shape (32,) for Tensor 'ph_input_labels:0', which has shape '(?, 1)
My guess is your labels in get_summary has the shape [32]. Can you just reshape it to (32, 1)? Or maybe reshape the label earlier in _parse_fn?

How to perform string find and replace on Tensorflow String Tensor?

I currently am using the Tensorflow dataset api to perform some augmentations to images at a specified path. The filename itself contains information that states whether to augment the file or not. So what I want to do is read in the files from the dataset and for each file, perform a find within the filename and if I find a specific substring, then set a bool flag and replace the substring with "".
The error I get is:
AttributeError: 'Tensor' object has no attribute 'find'
I can't perform a "find" on the tensor with dtype string entries because find is not a part of the Tensor, so I am trying to figure out how I can go about performing the above action. I have shared some code below that I think demonstrates what I am trying to do. Performance is important, so I would prefer to do this the correct way if anyone sees that I am going about doing this via the Dataset API incorrectly.
def preproc_img(filenames):
def parse_fn(filename):
augment_inst = False
if cfg.SPLIT_INTO_INST:
#*****************************************************
#*** THIS IS WHERE THE LOGIC IS CURRENTLY BREAKING ***
#*****************************************************
if filename.find('_data_augmentation') != -1:
augment_inst = True
filename = filename.replace('_data_augmentation', '')
image_string = tf.read_file(filename)
img = tf.image.decode_image(image_string, channels=3)
return dict(zip([filename], [img]))
dataset = tf.data.Dataset.from_tensor_slices(filenames)
dataset = dataset.map(parse_fn)
iterator = dataset.make_one_shot_iterator()
return iterator.get_next()
def perform_train():
if __name__ == '__main__':
filenames = helper.get_image_paths()
next_batch = preproc_img(filenames)
with tf.Session() as sess:
with sess .graph.as_default():
sess.run(tf.local_variables_initializer())
sess.run(tf.global_variables_initializer())
dat = sess.run(next_batch)
# I would now go about calling any of my tf op code below
You can use tf.regex_replace for replacing text in a tf.string tensor.
filename = tf.regex_replace(filename, "_data_augmentation", "")
For TF 2.0
filename = tf.strings.regex_replace(filename, "_data_augmentation", "")

How can I use tf.string_split() in tensorflow?

I want to get the extension of image files to invoke different image decoder, and I found there's a function called tf.string_split in tensorflow r0.11.
filename_queue = tf.train.string_input_producer(filenames, shuffle=shuffle)
reader = tf.WholeFileReader()
img_src, img_bytes = reader.read(filename_queue)
split_result = tf.string_split(img_src, '.')
But when I run it, I get this error:
ValueError: Shape must be rank 1 but is rank 0 for 'StringSplit' (op: 'StringSplit') with input shapes: [], [].
I think it may caused by the shape inference of img_src. I try to use img_src.set_shape([1,]) to fix it, but it seems not work, I get this error:
ValueError: Shapes () and (1,) are not compatible
Also, I can't get the shape of img_src using
tf.Print(split_result, [tf.shape(img_src)],'img_src shape=')
The result is img_src shape=[]. But if I use the following code:
tf.Print(split_result, [img_src],'img_src=')
The result is img_src=test_img/test1.png. Am I doing something wrong?
Just pack img_src into a tensor.
split_result = tf.string_split([img_src], '.')