Google Cloud Vision not automatically splitting images for trainin/test - google-cloud-platform

It's weird, for some reason GCP Vision won't allow me to train my model. I have met the minimum of 10 images per label, no images unlabeled and tried uploading a CSV pointing to 3 of this labels images as VALIDATION images.. Yet I get this error
Some of your labels (e.g. ‘Label1’) do not have enough images assigned to your Validation sets. Import another CSV file and assign those images to those sets.
any ideas would be appreciated

This error generally occurs when you did not labelled all the images because AutoML divides your images, including the mislabelled ones, into the categories and this error is triggered when the unlabelled images go to the VALIDATION set.
According to the documentation, it is recomended 1000 images per label. However, the minimum is 10 images for each label or 50 for complex cases. In addition,
The model works best when there are at most 100x more images for the most common label than for the least common label. We recommend removing very low frequency labels.
Furthermore, AutoML Vision uses the 80% of your content documents for training, 10% for validating, and 10% for testing. Since your images were not divided into these three categories, you should manually assign them to TRAIN, VALIDATION and TEST. You can do that by, uploading your images to a GCS bucket and referencing each labelled image in a .csv file, as follows:
TRAIN, gs://my_bucket/image1.jpeg,cat
As you can see above, it follows the format [SET],[GCS image path], [Label]. Note that you will be dividing your dataset manullay and it should respect the percentages already mentioned. Thus, you will have enough data in each category. You can follow the steps for preparing your training data here and here.
Note: please be aware that your .csv file is case sentive.
Lastly, in order to validate your dataset and inspect labelled/unlabelled images you can export the created dataset and check the exported .csv file. You can do it as described in the documentation. After exporting, download it and verify each SET( TRAIN, VALIDATION and TEST).

Related

Annotation specs - AutoML (GCP)

I'm using the Natural Language module on Google Cloud Platform and more specifically AUTOML for text classification.
I come across this error which I do not understand when I have finished importing my data and the text has been processed :
Error: The dataset has too many annotation specs, the maximum allowed number is 5000.
What does it mean? Have you already got it?
Thanks
Take a look at the AutoML Quotas & Limits documentation for better understanding.
It seems that you are touching the highest limit of labels per dataset. Check it on the AutoML limits --> Labels per dataset --> 2 - 5000 (for classification).
Take into account that limits, unlike quotas, cannot be increased.
I also got this error while I was certain that my number of labels are below 5000. It turns out to be an error with my CSV formatting.
When you create your text data using to_csv() in Pandas, it will only quotes that part of text data that contains comma, while AutoML Text wants you to quote all lines of the text. I have written the solution in this Stackoverflow answer

Amazon Sagemaker Groundtruth: Cannot get active learning to work

I am trying to test Sagemaker Groundtruth's active learning capability, but cannot figure out how to get the auto-labeling part to work. I started a previous labeling job with an initial model that I had to create manually. This allowed me to retrieve the model's ARN as a starting point for the next job. I uploaded 1,758 dataset objects and labeled 40 of them. I assumed the auto-labeling would take it from here, but the job in Sagemaker just says "complete" and is only displaying the labels that I created. How do I make the auto-labeler work?
Do I have to manually label 1,000 dataset objects before it can start working? I saw this post: Information regarding Amazon Sagemaker groundtruth, where the representative said that some of the 1,000 objects can be auto-labeled, but how is that possible if it needs 1,000 objects to start auto-labeling?
Thanks in advance.
I'm an engineer at AWS. In order to understand the "active learning"/"automated data labeling" feature, it will be helpful to start with a broader recap of how SageMaker Ground Truth works.
First, let's consider the workflow without the active learning feature. Recall that Ground Truth annotates data in batches [https://docs.aws.amazon.com/sagemaker/latest/dg/sms-batching.html]. This means that your dataset is submitted for annotation in "chunks." The size of these batches is controlled by the API parameter MaxConcurrentTaskCount [https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_HumanTaskConfig.html#sagemaker-Type-HumanTaskConfig-MaxConcurrentTaskCount]. This parameter has a default value of 1,000. You cannot control this value when you use the AWS console, so the default value will be used unless you alter it by submitting your job via the API instead of the console.
Now, let's consider how active learning fits into this workflow. Active learning runs in between your batches of manual annotation. Another important detail is that Ground Truth will partition your dataset into a validation set and an unlabeled set. For datasets smaller than 5,000 objects, the validation set will be 20% of your total dataset; for datasets largert than 5,000 objects, the validation set will be 10% of your total dataset. Once the validation set is collected, any data that is subsequently annotated manually consistutes the training set. The collection of the validation set and training set proceeds according to the batch-wise process described in the previous paragraph. A longer discussion of active learning is available in [https://docs.aws.amazon.com/sagemaker/latest/dg/sms-automated-labeling.html].
That last paragraph was a bit of a mouthful, so I'll provide an example using the numbers you gave.
Example #1
Default MaxConcurrentTaskCount ("batch size") of 1,000
Total dataset size: 1,758 objects
Computed validation set size: 0.2 * 1758 = 351 objects
Batch #
Annotate 351 objects to populate the validation set (1407 remaining).
Annotate 1,000 objects to populate the first iteration of the training set (407 remaining).
Run active learning. This step may, depending on the accuracy of the model at this stage, result in the annotation of zero, some, or all of the remaining 407 objects.
(Assume no objects were automatically labeled in step #3) Annotate 407 objects. End labeling job.
Example #2
Non-default MaxConcurrentTaskCount ("batch size") of 250
Total dataset size: 1,758 objects
Computed validation set size: 0.2 * 1758 = 351 objects
Batch #
Annotate 250 objects to begin populating the validation set (1508 remaining).
Annotate 101 objects to finish populating the validation set (1407 remaining).
Annotate 250 objects to populate the first iteration of the training set (1157 remaining).
Run active learning. This step may, depending on the accuracy of the model at this stage, result in the annotation of zero, some, or all of the remaining 1157 objects. All else being equal, we would expect the model to be less accurate than the model in example #1 at this stage, because our training set is only 250 objects here.
Repeat alternating steps of annotating batches of 250 objects and running active learning.
Hopefully these examples illustrate the workflow and help you understand the process a little better. Since your dataset consists of 1,758 objects, the upper bound on the number of automated labels that can be supplied is 407 objects (assuming you use the default MaxConcurrentTaskCount).
Ultimately, 1,758 objects is still a relatively small dataset. We typically recommend at least 5,000 objects to see meaningful results [https://docs.aws.amazon.com/sagemaker/latest/dg/sms-automated-labeling.html]. Without knowing any other details of your labeling job, it's difficult to gauge why your job didn't result in more automated annotations. A useful starting point might be to inspect the annotations you received, and to determine the quality of the model that was trained during the Ground Truth labeling job.
Best regards from AWS!

Google vision fails to identify numbers in a table

I am aiming to extract a table of text & numbers from a document using Google's Vision API. The results are far from satisfactory - Vision seems to completely miss the contents of 2 columns in my table.
Recognition rate improves when I manually erase the column border but I cannot pre-process each file which I intend to process.
Cropping the column text, MOVing the column text to a new location dont seem to make a difference.
Increasing the brightness/contrast of the document seems to help a little bit but not enough to be satisfactory.
I'm using the "Try-It" web interface at cloud.google.com/vision/docs/drag-and-drop to test all my experiments... It mimics the results of running my code on the document.
I'm uploading JPG images, created from scanned PDF originals (converted in photoshop).
I dont have any code since the problem shows up just using the web-tool.
many of the numbers are single digits but many are not.
The numbers missed are 1,3,4,8,500,1,16,100,10
Other columns (which ARE read ok) contain decimal numbers
Perhaps there are some tricks/tips that I've not found that I can use?

Training and Test Set in Weka InCompatible in Text Classification

I have two datasets regarding whether a sentence contains a mention of a drug adverse event or not, both the training and test set have only two fields the text and the labels{Adverse Event, No Adverse Event} I have used weka with the stringtoWordVector filter to build a model using Random Forest on the training set.
I want to test the model built with removing the class labels from the test data set, applying the StringToWordVector filter on it and testing the model with it. When I try to do that it gives me the error saying training and test set not compatible probably because the filter identifies a different set of attributes for the test dataset. How do I fix this and output the predictions for the test set.
The easiest way to do this for a one off test is not to pre-filter the training set, but to use Weka's FilteredClassifier and configure it with the StringToWordVector filter, and your chosen classifier to do the classification. This is explained well in this video from the More Data Mining with Weka online course.
For a more general solution, if you want to build the model once then evaluate it on different test sets in future, you need to use InputMappedClassifier:
Wrapper classifier that addresses incompatible training and test data
by building a mapping between the training data that a classifier has
been built with and the incoming test instances' structure. Model
attributes that are not found in the incoming instances receive
missing values, so do incoming nominal attribute values that the
classifier has not seen before. A new classifier can be trained or an
existing one loaded from a file.
Weka requires a label even for the test data. It uses the labels or „ground truth“ of the test data to compare the result of the model against it and measure the model performance. How would you tell whether a model is performing well, if you don‘t know whether its predictions are right or wrong. Thus, the test data needs to have the very same structure as the training data in WEKA, including the labels. No worries, the labels are not used to help the model with its predictions.
The best way to go is to select cross validation (e.g. 10 fold cross validation) which automatically will split your data into 10 parts, using 9 for training and the remaining 1 for testing. This procedure is repeated 10 times so that each of the 10 parts has once been used as test data. The final performance verdict will be an average of all 10 rounds. Cross validation gives you a quite realistic estimate of the model performance on new, unseen data.
What you were trying to do, namely using the exact same data for training and testing is a bad idea, because the measured performance you end up with is way too optimistic. This means, you‘ll get very impressive figures like 98% accuracy during testing - but as soon as you use the model against new unseen data your accuracy might drop to a much worse level.

How to do prediction with weka

i'm using weka to do some text mining, i'm a little bit confused so i'm here to ask how can i ( with a set of comments that are in a some way classified as: notes, status of work, not conformity, warning) predict if a new comment belong to a specific class, with all the comment (9551) i've done a preprocess obtaining with the filter "stringtowordvector" a vector of tokens, and then i've used the simple kmeans to obtain a number of cluster.
So the question is: if a user post a new comment can i predict with those data if it belong to a category of comment?
sorry if my question is a little bit confused but so am i.
thank you
Trivial Training-validation-test
Create two datasets from your labelled instances. One will be training set and the other will be validation set. The training set will contain about 60% of the labelled data and the validation will contain 40% of the labelled data. There is no hard and fast rule for this split, but a 60-40 split is a good choice.
Use K-means (or any other clustering algorithm) on your training data. Develop a model. Record the model's error on training set. If the error is low and acceptable, you are fine. Save the model.
For now, your validation set will be your test dataset. Apply the model you saved on your validation set. Record the error. What is the difference between training error and validation error? If they both are low, the model's generalization is "seemingly" good.
Prepare a test dataset where you have all the features of your training and test dataset but the class/cluster is unknown.
Apply the model on the test data.
10-fold cross validation
Use all of your labelled data instances for this task.
Apply K-means (or any other algorithm of your choice) with a 10-fold CV setup.
Record the training error and CV error. Are they low? Is the difference between the errors is low? If yes, then save the model and apply it on the test data whose class/cluster is unknown.
NB: The training/test/validation errors and their differences will give you an "very initial" idea of overfitting/underfitting of your model. They are sanity tests. You need to perform other tests like learning curves to see if your model overfits or underfits or perfect. If there appears to be an overfitting and underfitting problem, you need to try many different techniques to overcome them.