anomalib/docs/source/markdown/guides/how_to/data/custom_data.md

Custom Data

This tutorial will show you how to train anomalib models on your custom data. More specifically, we will show you how to use the Folder dataset to train anomalib models on your custom data.

This tutorial assumes that you have already installed anomalib.
If not, please refer to the installation section.

We will use our [hazelnut_toy](https://github.com/open-edge-platform/anomalib/releases/download/hazelnut_toy_dataset/hazelnut_toy.zip) dataset to show the capabilities of the [Folder](../../reference/data/image/folder.md)
dataset, but you can use any dataset you want.

We will split the section to two tasks: Classification and Segmentation.

Classification Dataset

In certain use-cases, ground-truth masks for the abnormal images may not be available. In such cases, we could use the classification task to train a model that will be able to detect the abnormal images in the test set.

We will split this section into two tasks:

• Classification with normal and abnormal images, and
• Classification with only normal images.

With Normal and Abnormal Images

We could use Folder datamodule to train a model on this dataset. We could run the following python code to create the custom datamodule:

:::::{dropdown} Code Syntax :icon: code

::::{tab-set} :::{tab-item} API :sync: label-1

:language: python

As can be seen above, we only need to specify the ``task`` argument to ``classification``. We could have also use ``TaskType.CLASSIFICATION`` instead of ``classification``.

The Folder datamodule will create training, validation, test and prediction datasets and dataloaders for us. We can access the datasets and dataloaders by following the same approach as in the segmentation task.

When we check the samples from the dataloaders, we will see that the mask key is not present in the samples. This is because we do not need the masks for the classification task.

:language: python

Training the model is as simple as running the following command:

:language: python

where we train a Patchcore model on this custom dataset with default model parameters.

:::

:::{tab-item} CLI :sync: label-2

Here is the dataset config to create the same custom datamodule:

:language: yaml

Assume that we have saved the above config file as classification.yaml. We could run the following CLI command to train a Patchcore model on above dataset:

anomalib train --data classification.yaml --model anomalib.models.Patchcore --task CLASSIFICATION

As can be seen above, we also need to specify the ``task`` argument to ``CLASSIFICATION`` to explicitly tell anomalib that we want to train a classification model. This is because the default `task` is `SEGMENTATION` within `Engine`.

::: :::: :::::

With Only Normal Images

There are certain cases where we only have normal images in our dataset but would like to train a classification model.

This could be done in two ways:

• Train the model and skip the validation and test steps, as we do not have abnormal images to validate and test the model on, or
• Use the synthetic anomaly generation feature to create abnormal images from normal images, and perform the validation and test steps.

For now we will focus on the second approach.

With Validation and Testing via Synthetic Anomalies

If we want to check the performance of the model, we will need to have abnormal images to validate and test the model on. During the validation stage, these anomalous images are used to normalize the anomaly scores and find the best threshold that separates normal and abnormal images.

Anomalib provides synthetic anomaly generation capabilities to create abnormal images from normal images so we could check the performance. We could use the Folder datamodule to train a model on this dataset.

:::::{dropdown} Code Syntax :icon: code

::::{tab-set} :::{tab-item} API :sync: label-1

:language: python

Once the datamodule is setup, the rest of the process is the same as in the previous classification example.

:language: python

where we train a Patchcore model on this custom dataset with default model parameters.

:::

:::{tab-item} CLI :sync: label-2

Here is the CLI command to create the same custom datamodule with only normal images. We only need to change the test_split_mode argument to SYNTHETIC to generate synthetic anomalies.

:language: yaml

Assume that we have saved the above config file as normal.yaml. We could run the following CLI command to train a Patchcore model on above dataset:

anomalib train --data normal.yaml --model anomalib.models.Patchcore --task CLASSIFICATION

As shown in the previous classification example, we, again, need to specify the ``task`` argument to ``CLASSIFICATION`` to explicitly tell anomalib that we want to train a classification model. This is because the default `task` is `SEGMENTATION` within `Engine`.

::: :::: :::::

Segmentation Dataset

Assume that we have a dataset in which the training set contains only normal images, and the test set contains both normal and abnormal images. We also have masks for the abnormal images in the test set. We want to train an anomaly segmentation model that will be able to detect the abnormal regions in the test set.

With Normal and Abnormal Images

We could use Folder datamodule to load the hazelnut dataset in a format that is readable by Anomalib's models.

:::::{dropdown} Code Syntax ::::{tab-set} :::{tab-item} API :sync: label-1

We could run the following python code to create the custom datamodule:

:language: python

The Folder datamodule will create training, validation, test and prediction datasets and dataloaders for us. We can access the datasets and dataloaders using the following attributes:

:language: python

To check what individual samples from dataloaders look like, we can run the following command:

:language: python

We could check the shape of the images and masks using the following commands:

print(train_data["image"].shape)
# torch.Size([32, 3, 256, 256])

print(train_data["mask"].shape)
# torch.Size([32, 256, 256])

Training the model is as simple as running the following command:

:language: python

where we train a Patchcore model on this custom dataset with default model parameters. :::

:::{tab-item} CLI :sync: label-2 Here is the CLI command to create the same custom datamodule:

:language: yaml

Assume that we have saved the above config file as segmentation.yaml. We could run the following CLI command to train a Patchcore model on above dataset:

anomalib train --data segmentation.yaml --model anomalib.models.Patchcore

:::

:::: :::::

This example demonstrates how to create a segmentation dataset with normal and abnormal images. We could expand this example to create a segmentation dataset with only normal images.

With Only Normal Images

There are certain cases where we only have normal images in our dataset but would like to train a segmentation model. This could be done in two ways:

• Train the model and skip the validation and test steps, as we do not have abnormal images to validate and test the model on, or
• Use the synthetic anomaly generation feature to create abnormal images from normal images, and perform the validation and test steps.

For now we will focus on the second approach.

With Validation and Testing via Synthetic Anomalies

We could use the synthetic anomaly generation feature again to create abnormal images from normal images. We could then use the Folder datamodule to train a model on this dataset. Here is the python code to create the custom datamodule:

:::::{dropdown} Code Syntax :icon: code

::::{tab-set} :::{tab-item} API :sync: label-1

We could run the following python code to create the custom datamodule:

:language: python

As can be seen from the code above, we only need to specify the test_split_mode argument to SYNTHETIC. The Folder datamodule will create training, validation, test and prediction datasets and dataloaders for us.

To check what individual samples from dataloaders look like, we can run the following command:

:language: python

We could check the shape of the images and masks using the following commands:

print(train_data["image"].shape)
# torch.Size([32, 3, 256, 256])

print(train_data["mask"].shape)
# torch.Size([32, 256, 256])

:::

:::{tab-item} CLI :sync: label-2

Here is the CLI command to create the same custom datamodule with only normal images. We only need to change the test_split_mode argument to SYNTHETIC to generate synthetic anomalies.

:language: yaml

Assume that we have saved the above config file as synthetic.yaml. We could run the following CLI command to train a Patchcore model on above dataset:

anomalib train --data synthetic.yaml --model anomalib.models.Patchcore

::: :::: :::::