When to use data augmentation in validation sets?

When to use data augmentation in validation sets?

This answer on stats.SE makes the case for applying crops on the validation / test sets so as to make that input similar the the input in the training set that the network was trained on. Data augmentation is done only on training set as it helps the model become more generalize and robust. So there’s no point of augmenting the test set.

How is data augmentation used in machine learning?

Data augmentation is used to increase the size of training set and to get more different images. Technically, you could use data augmentation on test set to see how model behaves on such images, but usually people don’t do it.

When is it OK to validate only with the original images?

Ideally, data augmentation is a step in your training pipeline, which comes after splitting your data into train/validation/test sets. Otherwise, you have the same data point in both training and testing, even if it a little rotated. So your training pipeline could be something like this:

How is data augmentation used in computer vision?

In computer vision, you can use data augmentation during test time to obtain different views on the test image. You then have to aggregate the results obtained from each image for example by averaging them.

Is there a problem with adding validation data?

The point of adding validation data is to build generalized model so it is nothing but to predict real-world data. inorder to predict real-world data, the validation set should contain real data. There is no problem with augmenting validation data but it won’t increase the accuracy of the model.

Why is data augmentation done only on training set?

Data augmentation is done only on training set as it helps the model become more generalize and robust. So there’s no point of augmenting the test set. Do it only on the training set. The reason why we use a training and a test set in the first place is that we want to estimate the error our system will have in reality.

Which is the best example of data augmentation?

This is, of course, an incredibly simplified example. You more than likely have more than a single image — you probably have 10s or 100s of images and now your goal is to turn that smaller set into 1000s of images for training. In those situations, dataset expansion and dataset generation may be worth exploring.

Which is better offline or online data augmentation?

Online augmentation model will see different images at each epoch. In Offline augmentation, augmented image is part of the training set, it views the augmented image multiple times depending on the number of epochs. The model generalizes better with online augmentation as it sees more samples during training with online data augmentation.