How to convert TFRecord file from YouTube8M dataset into a format for use with Opencv? - opencv

As the title suggest, I am trying to obtain individual videos from YouTube8M dataset and I wish to apply them to the cv2.VideoCapture() function as seen in this page:
https://opencv24-python-tutorials.readthedocs.io/en/latest/py_tutorials/py_video/py_lucas_kanade/py_lucas_kanade.html
I am struggling with understanding how I can create a parse function that can be used for the YouTube8M videos. Any suggestions will be much appreciated.
I have seen examples where the Parse function is structured as follows:
def parse_example(example_proto):
# Define the features in the example
feature_description = {
'height': tf.io.FixedLenFeature([], tf.int64),
'width': tf.io.FixedLenFeature([], tf.int64),
'depth': tf.io.FixedLenFeature([], tf.int64),
'frame': tf.io.FixedLenFeature([], tf.string),
}
However the YouTube8M data has the following features, "id", "labels", "mean_rgb" and "audio"
(reference link, https://research.google.com/youtube8m/download.html)

Related

How to save sentence-Bert output vectors to a file?

I am using Bert to get similarity between multi term words.here is my code that I used for embedding :
from sentence_transformers import SentenceTransformer
model = SentenceTransformer('bert-large-uncased-whole-word-masking')
words = [
"Artificial intelligence",
"Data mining",
"Political history",
"Literature book"]
I also have a dataset which contains 540000 other words.
Vocabs = [
"Winter flooding",
"Cholesterol diet", ....]
the problem is when I want to embed Vocabs to vectors it takes time forever.
words_embeddings = model.encode(words)
Vocabs_embeddings = model.encode(Vocabs)
is there any way to make it faster? or I want to embed Vocabs in for loops and save the output vectors in a file so I don't have to embed 540000 vocabs every time I need it. is there a way to save embeddings to a file and use it again?
I will really appreciate you for your time trying help me.
You can pickle your corpus and embeddings like this, you can also pickle a dictionary instead, or write them to file in any other format you prefer.
import pickle
with open("my-embeddings.pkl", "wb") as fOut:
pickle.dump({'sentences': words, 'embeddings': word_embeddings},fOut)
Or more generally like below, so you encode when the embeddings don't exist but after that any time you need them you load from file, instead of re-encoding your corpus:
if not os.path.exists(embedding_cache_path):
# read your corpus etc
corpus_sentences = ...
print("Encoding the corpus. This might take a while")
corpus_embeddings = model.encode(corpus_sentences, show_progress_bar=True, convert_to_numpy=True)
corpus_embeddings = corpus_embeddings / np.linalg.norm(corpus_embeddings, axis=1, keepdims=True)
print("Storing file on disc")
with open(embedding_cache_path, "wb") as fOut:
pickle.dump({'sentences': corpus_sentences, 'embeddings': corpus_embeddings}, fOut)
else:
print("Loading pre-computed embeddings from disc")
with open(embedding_cache_path, "rb") as fIn:
cache_data = pickle.load(fIn)
corpus_sentences = cache_data['sentences']
corpus_embeddings = cache_data['embeddings']

Doc2vec: Only 10 docvecs in gensim doc2vec model?

I used gensim fit a doc2vec model, with tagged document (length>10) as training data. The target is to get doc vectors of all training docs, but only 10 vectors can be found in model.docvecs.
The example of training data (length>10)
docs = ['This is a sentence', 'This is another sentence', ....]
with some pre-treatment
doc_=[d.strip().split(" ") for d in doc]
doc_tagged = []
for i in range(len(doc_)):
tagd = TaggedDocument(doc_[i],str(i))
doc_tagged.append(tagd)
tagged docs
TaggedDocument(words=array(['a', 'b', 'c', ..., ],
dtype='<U32'), tags='117')
fit a doc2vec model
model = Doc2Vec(min_count=1, window=10, size=100, sample=1e-4, negative=5, workers=8)
model.build_vocab(doc_tagged)
model.train(doc_tagged, total_examples= model.corpus_count, epochs= model.iter)
then i get the final model
len(model.docvecs)
the result is 10...
I tried other datasets (length>100, 1000) and got same result of len(model.docvecs).
So, my question is:
How to use model.docvecs to get full vectors? (without using model.infer_vector)
Is model.docvecs designed to provide all training docvecs?
The bug is in this line:
tagd = TaggedDocument(doc[i],str(i))
Gensim's TaggedDocument accepts a sequence of tags as a second argument. When you pass a string '123', it's turned into ['1', '2', '3'], because it's treated as a sequence. As a result, all of the documents are tagged with just 10 tags ['0', ..., '9'], in various combinations.
Another issue: you're defining doc_ and never actually using it, so your documents will be split incorrectly as well.
Here's the proper solution:
docs = [doc.strip().split(' ') for doc in docs]
tagged_docs = [doc2vec.TaggedDocument(doc, [str(i)]) for i, doc in enumerate(docs)]

How do I use Conll 2003 corpus in python crfsuite

I have downloaded Conll 2003 corpus ("eng.train"). I want to use it to extract entity using python crfsuite training. But I don't know how to load this file for training.
I found this example, but it is not for English.
train_sents = list(nltk.corpus.conll2002.iob_sents('esp.train'))
test_sents = list(nltk.corpus.conll2002.iob_sents('esp.testb'))
Also in future I would like to train new entities other than POS or location. How can I add those.
Also please suggest how to handle multiple words.
You can use ConllCorpusReader.
Here a general impelemantation:
ConllCorpusReader('file path', 'file name', columntypes=['','',''])
Here a list of column types which you can use: 'WORDS', 'POS', 'TREE', 'CHUNK', 'NE', 'SRL', 'IGNORE'
Example:
from nltk.corpus.reader import ConllCorpusReader
train = ConllCorpusReader('CoNLL-2003', 'eng.train', ['words', 'pos', 'ignore', 'chunk'])
test = ConllCorpusReader('CoNLL-2003', 'eng.testa', ['words', 'pos', 'ignore', 'chunk'])

Keras Text Preprocessing - Saving Tokenizer object to file for scoring

I've trained a sentiment classifier model using Keras library by following the below steps(broadly).
Convert Text corpus into sequences using Tokenizer object/class
Build a model using the model.fit() method
Evaluate this model
Now for scoring using this model, I was able to save the model to a file and load from a file. However I've not found a way to save the Tokenizer object to file. Without this I'll have to process the corpus every time I need to score even a single sentence. Is there a way around this?
The most common way is to use either pickle or joblib. Here you have an example on how to use pickle in order to save Tokenizer:
import pickle
# saving
with open('tokenizer.pickle', 'wb') as handle:
pickle.dump(tokenizer, handle, protocol=pickle.HIGHEST_PROTOCOL)
# loading
with open('tokenizer.pickle', 'rb') as handle:
tokenizer = pickle.load(handle)
Tokenizer class has a function to save date into JSON format:
tokenizer_json = tokenizer.to_json()
with io.open('tokenizer.json', 'w', encoding='utf-8') as f:
f.write(json.dumps(tokenizer_json, ensure_ascii=False))
The data can be loaded using tokenizer_from_json function from keras_preprocessing.text:
with open('tokenizer.json') as f:
data = json.load(f)
tokenizer = tokenizer_from_json(data)
The accepted answer clearly demonstrates how to save the tokenizer. The following is a comment on the problem of (generally) scoring after fitting or saving. Suppose that a list texts is comprised of two lists Train_text and Test_text, where the set of tokens in Test_text is a subset of the set of tokens in Train_text (an optimistic assumption). Then fit_on_texts(Train_text) gives different results for texts_to_sequences(Test_text) as compared with first calling fit_on_texts(texts) and then text_to_sequences(Test_text).
Concrete Example:
from keras.preprocessing.text import Tokenizer
docs = ["A heart that",
"full up like",
"a landfill",
"no surprises",
"and no alarms"
"a job that slowly"
"Bruises that",
"You look so",
"tired happy",
"no alarms",
"and no surprises"]
docs_train = docs[:7]
docs_test = docs[7:]
# EXPERIMENT 1: FIT TOKENIZER ONLY ON TRAIN
T_1 = Tokenizer()
T_1.fit_on_texts(docs_train) # only train set
encoded_train_1 = T_1.texts_to_sequences(docs_train)
encoded_test_1 = T_1.texts_to_sequences(docs_test)
print("result for test 1:\n%s" %(encoded_test_1,))
# EXPERIMENT 2: FIT TOKENIZER ON BOTH TRAIN + TEST
T_2 = Tokenizer()
T_2.fit_on_texts(docs) # both train and test set
encoded_train_2 = T_2.texts_to_sequences(docs_train)
encoded_test_2 = T_2.texts_to_sequences(docs_test)
print("result for test 2:\n%s" %(encoded_test_2,))
Results:
result for test 1:
[[3], [10, 3, 9]]
result for test 2:
[[1, 19], [5, 1, 4]]
Of course, if the above optimistic assumption is not satisfied and the set of tokens in Test_text is disjoint from that of Train_test, then test 1 results in a list of empty brackets [].
I've created the issue https://github.com/keras-team/keras/issues/9289 in the keras Repo. Until the API is changed, the issue has a link to a gist that has code to demonstrate how to save and restore a tokenizer without having the original documents the tokenizer was fit on. I prefer to store all my model information in a JSON file (because reasons, but mainly mixed JS/Python environment), and this will allow for that, even with sort_keys=True
I found the following snippet provided at following link by #thusv89.
Save objects:
import pickle
with open('data_objects.pickle', 'wb') as handle:
pickle.dump(
{'input_tensor': input_tensor,
'target_tensor': target_tensor,
'inp_lang': inp_lang,
'targ_lang': targ_lang,
}, handle, protocol=pickle.HIGHEST_PROTOCOL)
Load objects:
with open("dataset_fr_en.pickle", 'rb') as f:
data = pickle.load(f)
input_tensor = data['input_tensor']
target_tensor = data['target_tensor']
inp_lang = data['inp_lang']
targ_lang = data['targ_lang']
Quite easy, because Tokenizer class has provided two funtions for save and load:
save —— Tokenizer.to_json()
load —— keras.preprocessing.text.tokenizer_from_json
In to_json() method,it call "get_config" method which handle this:
json_word_counts = json.dumps(self.word_counts)
json_word_docs = json.dumps(self.word_docs)
json_index_docs = json.dumps(self.index_docs)
json_word_index = json.dumps(self.word_index)
json_index_word = json.dumps(self.index_word)
return {
'num_words': self.num_words,
'filters': self.filters,
'lower': self.lower,
'split': self.split,
'char_level': self.char_level,
'oov_token': self.oov_token,
'document_count': self.document_count,
'word_counts': json_word_counts,
'word_docs': json_word_docs,
'index_docs': json_index_docs,
'index_word': json_index_word,
'word_index': json_word_index
}

How to fetch vectors for a word list with Word2Vec?

I want to create a text file that is essentially a dictionary, with each word being paired with its vector representation through word2vec. I'm assuming the process would be to first train word2vec and then look-up each word from my list and find its representation (and then save it in a new text file)?
I'm new to word2vec and I don't know how to go about doing this. I've read from several of the main sites, and several of the questions on Stack, and haven't found a good tutorial yet.
The direct access model[word] is deprecated and will be removed in Gensim 4.0.0 in order to separate the training and the embedding. The command should be replaced with, simply, model.wv[word].
Using Gensim in Python, after vocabs are built and the model trained, you can find the word count and sampling information already mapped in model.wv.vocab, where model is the variable name of your Word2Vec object.
Thus, to create a dictionary object, you may:
my_dict = dict({})
for idx, key in enumerate(model.wv.vocab):
my_dict[key] = model.wv[key]
# Or my_dict[key] = model.wv.get_vector(key)
# Or my_dict[key] = model.wv.word_vec(key, use_norm=False)
Now that you have your dictionary, you can write it to a file with whatever means you like. For example, you can use the pickle library. Alternatively, if you are using Jupyter Notebook, they have a convenient 'magic command' %store my_dict > filename.txt. Your filename.txt will look like:
{'one': array([-0.06590105, 0.01573388, 0.00682817, 0.53970253, -0.20303348,
-0.24792041, 0.08682659, -0.45504045, 0.89248925, 0.0655603 ,
......
-0.8175681 , 0.27659689, 0.22305458, 0.39095637, 0.43375066,
0.36215973, 0.4040089 , -0.72396156, 0.3385369 , -0.600869 ],
dtype=float32),
'two': array([ 0.04694849, 0.13303463, -0.12208422, 0.02010536, 0.05969441,
-0.04734801, -0.08465996, 0.10344813, 0.03990637, 0.07126121,
......
0.31673026, 0.22282903, -0.18084198, -0.07555179, 0.22873943,
-0.72985399, -0.05103955, -0.10911274, -0.27275378, 0.01439812],
dtype=float32),
'three': array([-0.21048863, 0.4945509 , -0.15050395, -0.29089224, -0.29454648,
0.3420335 , -0.3419629 , 0.87303966, 0.21656844, -0.07530259,
......
-0.80034876, 0.02006451, 0.5299498 , -0.6286509 , -0.6182588 ,
-1.0569025 , 0.4557548 , 0.4697938 , 0.8928275 , -0.7877308 ],
dtype=float32),
'four': ......
}
You may also wish to look into the native save / load methods of Gensim's word2vec.
Gensim tutorial explains it very clearly.
First, you should create word2vec model - either by training it on text, e.g.
model = Word2Vec(sentences, size=100, window=5, min_count=5, workers=4)
or by loading pre-trained model (you can find them here, for example).
Then iterate over all your words and check for their vectors in the model:
for word in words:
vector = model[word]
Having that, just write word and vector formatted as you want.
You can Directly get the vectors through
model = Word2Vec(sentences, size=100, window=5, min_count=5, workers=4)
model.wv.vectors
and words through
model.wv.vocab.keys()
Hope it helps !
If you are willing to use python with gensim package, then building upon this answer and Gensim Word2Vec Documentation you could do something like this
from gensim.models import Word2Vec
# Take some sample sentences
tokenized_sentences = [["here","is","one"],["and","here","is","another"]]
# Initialise model, for more information, please check the Gensim Word2vec documentation
model = Word2Vec(tokenized_sentences, size=100, window=2, min_count=0)
# Get the ordered list of words in the vocabulary
words = model.wv.vocab.keys()
# Make a dictionary
we_dict = {word:model.wv[word] for word in words}
Gensim 4.0 updates: vocab method is depreciated and change in how to parse a word's vector
Get the ordered list of words in the vocabulary
words = list(w for w in model.wv.index_to_key)
Get the vector for 'also'
print(model.wv['also'])
Using basic python:
all_vectors = []
for index, vector in enumerate(model.wv.vectors):
vector_object = {}
vector_object[list(model.wv.vocab.keys())[index]] = vector
all_vectors.append(vector_object)
For gensim 4.0:
my_dict = dict({})
for word in word_list:
my_dict[word] = model.wv.get_vector('0', norm = True)
I would suggest this, you may find anything you need including Word2Vec, FastText, Doc2Vec, KeyedVectors and so on...

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