clearml-docs/docs/hyperdatasets/dataviews.md

---
title: Dataviews
---

Dataviews is a powerful and easy-to-use **ClearML Enterprise** feature for creating and managing local views of remote 
Datasets. Dataviews can use sophisticated queries to input data from a subset of a Dataset 
or combinations of Datasets. 

Dataviews support:

* Filtering by ROI labels, frame metadata, and data sources
* Data debiasing to adjust for imbalanced data
* ROI label mapping (label translation)
* Class label enumeration
* Controls for the frame iteration, such as sequential or random iteration, limited or infinite iteration, and reproducibility. 

Dataviews are lazy and optimize processing. When an experiment script runs in a local environment, Dataview pointers
are initialized. If the experiment is cloned or extended, and that newly cloned or extended experiment is tuned and run, 
only changed pointers are initialized. The pointers that did not change are reused.

## Filtering

A Dataview filters experiment input data, using one or more frame filters. A frame filter defines the criteria for the 
selection of SingleFrames iterated by a Dataview.  

A frame filter contains the following criteria:

* Dataset version - Choose whether the filter applies to one version or all versions of a Dataset.
* Any combination of the following rules:

    * ROI rule - Include or exclude frames containing at least one ROI with any combination of labels in the Dataset version. 
      Optionally, limit the number of matching ROIs (instances) per frame, and / or limit the confidence level of the label.  
      For example: include frames containing two to four ROIs labeled `cat` and `dog`, with a confidence level from `0.8` to `1.0`.
    * Frame rule - Filter by frame metadata key-value pairs, or ROI labels.   
      For example: if some frames contain the metadata 
      key `dangerous` with values of `yes` or `no`, filter `(meta.dangerous:'yes')`.
    * Source rule - Filter by frame `source` dictionary key-value pairs.  
      For example: filter by source ID `(source.id:00)`.

* A ratio (weight) allowing to debias input data, to and adjust an imbalance in SingleFrames iterated by the Dataview (optional).

Use combinations of these frame filters to build sophisticated queries.

## Debiasing input data

Apply debiasing to each frame filter to adjust for an imbalance in input data. Ratios (weights) enable setting the proportion 
of frames that are inputted, according to any of the criteria in a frame filter, including ROI labels, frame metadata, 
and sources, as well as each Dataset version compared with the others. 

For example, data may contain five times the number of frames labeled `daylight` as those labeled `nighttime`, but 
you want to input the same number of both. To debias the data, create two frame filters, one for `daylight` with a ratio 
of `1`, and the other for `nighttime` with a ratio of `5`. The Dataview will iterate approximately an equal number of 
SingleFrames for each. 

## ROI Label mapping (label translation)

ROI label mapping (label translation) applies to the new model. For example, apply mapping to:

* Combine different labels under another more generic label.
* Consolidate disparate datasets containing different names for the ROI.
* Hide labeled objects from the training process.

## Class label enumeration

Define class labels for the new model and assign integers to each in order to maintain data conformity across multiple 
codebases and datasets. It is important to set enumeration values for all labels of importance. 

## Data augmentation

On-the-fly data augmentation is applied to SingleFrames, transforming images without creating new data. Apply data augmentation 
in steps, where each step is composed of a method, an operation, and a strength as follows: 

* **Affine** augmentation method - Transform an image's geometric shape to another position on a 2-dimensional plane.  
  Use any of the following operations:

    * Rotate
    * Reflect-horiz - Flip images horizontally
    * Reflect-vert - Flip images vertically
    * Scale
    * Shear - Skew
    * No operation - Randomly select SingleFrames that are not transformed (skipped). If the experiment runs again, and 
      the random seed in [iteration control](#iteration-control) is unchanged, the same SingleFrames are not augmented.
    
* **Pixel** augmentation method - Transform images by modifying pixel values while retaining shape and perspective.  
  Use any of the following operations:

    * Blur - Gaussian smoothing 
    * Noise - **ClearML Enterprise**'s own noise augmentation consisting of: 
      * **high** noise - like snow on analog televisions with a weak TV signal 
      * **low** noise - like a low resolution image magnified in localized areas on the image
    * Recolor - using an internal RGB lookup-table
    * No operation - Randomly select SingleFrames that are not transformed (skipped). If the experiment runs again, and 
      the random seed in [iteration control](#iteration-control) is unchanged, the same SingleFrames are not augmented.
    
* Strength - A number applied to adjust the degree of transformation. The recommended strengths are the following:

    * 0.0 - No effect
    * 0.5 - Low (weak)
    * 1.0 - Medium (recommended)
    * 2.0 - High (strong)

## Iteration control

The input data **iteration control** settings determine the order, number, timing, and reproducibility of the Dataview iterating 
SingleFrames. Depending upon the combination of iteration control settings, all SingleFrames may not be iterated, and some 
may repeat. The settings include the following:

* Order - Order of the SingleFrames returned by the iteration, which can be either:

    * Sequential - Iterate SingleFrames in sorted order by context ID and timestamp.
    * Random - Iterate SingleFrames randomly using a random seed that can be set (see Random Seed below).

* Repetition - The repetition of SingleFrames that, in conjunction with the order, determines whether all SingleFrames 
  are returned, and whether any may repeat. The repetition settings and their impact on iteration are the following:

    * Use Each Frame Once - All SingleFrames are iterated. If the order is sequential, then no SingleFrames repeat. If 
      the order is random, then some SingleFrames may repeat. 

    * Limit Frames - The maximum number of SingleFrames to iterate, unless the actual number of SingleFrames is fewer than 
      the maximum, then the actual number of SingleFrames are iterated. If the order is sequential, then no SingleFrames 
      repeat. If the order is random, then some SingleFrames may repeat. 

    * Infinite Iterations - Iterate SingleFrames until the experiment is manually terminated. If the order is sequential, 
      then all SingleFrames are iterated (unless the experiment is manually terminated before all iterate) and SingleFrames 
      repeat. If the order is random, then all SingleFrames may not be iterated, and some SingleFrames may repeat.
        
* Random Seed - If the experiment is rerun and the seed remains unchanged, the SingleFrames iteration is the same.

* Clip Length - For video data sources, in the number of sequential SingleFrames from a clip to iterate.

## Usage

### Creating Dataviews

Use the [`allegroai.DataView`](google.com) class to create a DataView object. Instantiate DataView objects, specifying 
iteration settings and additional iteration parameters that control query iterations. 

```python
from allegroai import DataView, IterationOrder
# Create a DataView object that iterates randomly until terminated by the user
myDataView = DataView(iteration_order=IterationOrder.random, iteration_infinite=True)
```

### Adding queries

To add a query to a DataView, use the [`DataView.add_query`](google.com) method and specify Dataset versions, 
ROI and / or frame queries, and other criteria. 

The `dataset_name` and `version_name` arguments specify the Dataset Version. The `roi_query` and `frame_query` arguments 
specify the queries. 
* `roi_query` can be assigned ROI labels by label name or Lucene queries.
* `frame_query` must be assigned a Lucene query. 
  
Multiple queries can be added to the same or different Dataset versions, each query with the same or different ROI 
and / or frame queries.

#### ROI queries: 

* ROI query for a single label

This example is an ROI query filtering for frames containing at least one ROI with the label `cat`.

```python
# Create a Dataview object for an iterator that randomly returns frames according to queries
myDataView = DataView(iteration_order=IterationOrder.random, iteration_infinite=True)

# Add a query for a Dataset version 
myDataView.add_query(dataset_name='myDataset',
                     version_name='myVersion', roi_query='cat')
```

* ROI query for one label OR another

This example is an ROI query filtering for frames containing at least one ROI with the label `cat` OR `dog`:

```python
# Add a query for a Dataset version 
myDataView.add_query(dataset_name='myDataset', version_name='myVersion', 
                     roi_query='cat')

myDataView.add_query(dataset_name='myDataset', version_name='myVersion', 
                     roi_query='dog')
```

* ROI query for one label AND another label  

This example is an ROI query filtering for frames containing at least one ROI with the label `Car` AND `partly_occluded`.

```python
# Add a query for a Dataset version
myDataView.add_query(dataset_name='myDataset', version_name='training',
                     roi_query=['Car','partly_occluded'])
```

* ROI query for one label AND NOT another (Lucene query).    

This example is an ROI query filtering for frames containing at least one ROI with the label `Car` AND NOT the label 
  `partly_occluded`.

```python
# Add a query for a Dataset version
# Use a Lucene Query
#   "label" is a key in the rois dictionary of a frame
#   In this Lucene Query, specify two values for the label key and use a Logical AND NOT
myDataView.add_query(dataset_name='myDataset', version_name='training',
    roi_query='label.keyword:\"Car\" AND NOT label.keyword:\"partly_occluded\"')
```

#### Querying multiple Datasets and versions

This example demonstrates an ROI query filtering for frames containing the ROI labels `car`, `truck`, or `bicycle` 
from two versions of one Dataset, and one version of another Dataset.

```python
# Add queries:

# The 1st Dataset version 
myDataView.add_query(dataset_name='dataset_1',
                     version_name='version_1',
                     roi_query='label.keyword:\"car\" OR label.keyword:\"truck\" OR '
                               'label.keyword:\"bicycle\"')

# The 1st Dataset, but a different version
myDataView.add_query(dataset_name='dataset_1',
                     version_name='version_2',
                     roi_query='label.keyword:\"car\" OR label.keyword:\"truck\" OR '
                               'label.keyword:\"bicycle\"')

# A 2nd Dataset (version)
myDataView.add_query(dataset_name='dataset_2', 
                     version_name='some_version',
                     roi_query='label.keyword:\"car\" OR label.keyword:\"truck\" OR '
                               'label.keyword:\"bicycle\"')

```

#### Frame queries

Use frame queries to filter frames by ROI labels and / or frame metadata key-value pairs that a frame must include or 
exclude for the DataView to return the frame. 

**Frame queries** match frame meta key-value pairs, ROI labels, or both.
They use the same logical OR, AND, NOT AND matching as ROI queries.

This example demonstrates a frame query filtering for frames containing the meta key `city` value of `bremen`.
        
```python
# Add a frame query for frames with the meta key "city" value of "bremen"
myDataView.add_query(dataset_name='myDataset',
                     version_name='version',
                     frame_query='meta.city:"bremen"')
```


### Controlling query iteration

Use [`DataView.set_iteration_parameters`](google.com) to manage the order, number, timing, and reproducibility of frames 
for training.


#### Iterate frames infinitely 

This example demonstrates creating a Dataview and setting its parameters to iterate infinitely until the script is 
manually terminated. 

```python
# Create a Dataview object for an iterator that returns frames
myDataView = DataView()

# Set Iteration Parameters (overrides parameters in constructing the DataView object
myDataView.set_iteration_parameters(order=IterationOrder.random, infinite=True)
```

#### Iterate all frames matching the query
This example demonstrates creating a DataView and setting its parameters to iterate and return all frames matching a query.

```python
# Create a Dataview object for an iterator for frames
myDataView = DataView(iteration_order=IterationOrder.random, iteration_infinite=True)

# Set Iteration Parameters (overrides parameters in constructing the DataView object
myDataView.set_iteration_parameters(
    order=IterationOrder.random, infinite=False)

# Add a query for a Dataset version 
myDataView.add_query(dataset_name='myDataset',
                     version_name='myVersion', roi_query='cat')
```

#### Iterate a maximum number of frames
This example demonstrates creating a DataView and setting its parameters to iterate a specific number of frames. If the 
Dataset version contains fewer than that number of frames matching the query, then fewer are returned by the iterator.

```python
# Create a Dataview object for an iterator for frames
myDataView = DataView(iteration_order=IterationOrder.random, iteration_infinite=True)

# Set Iteration Parameters (overrides parameters in constructing the DataView object
myDataView.set_iteration_parameters(
    order=IterationOrder.random, infinite=False,
    maximum_number_of_frames=5000)
```

### Debiasing input data

Debias input data using the [DataView.add_query](google.com) method's [weight](google.com) argument to add weights. This 
is the same [DataView.add_query](google.com) that can be used to specify Dataset versions, and ROI queries and frame queries.

This example adjusts an imbalance in the input data to improve training for `Car` ROIs that are also `largely occluded` 
(obstructed). For every frame containing at least one ROI labeled `Car`, approximately five frames containing at least 
one ROI labeled with both `Car` and `largely_occluded` will be input.

```python
myDataView = DataView(iteration_order=IterationOrder.random, iteration_infinite=True)

myDataView.add_query(dataset_name='myDataset', version_name='training', 
                     roi_query='Car', weight = 1)

myDataView.add_query(dataset_name='myDataset', version_name='training', 
                     roi_query='label.keyword:\"Car\" AND label.keyword:\"largely_occluded\"', weight = 5)
```

### Mapping ROI Labels

ROI label translation (label mapping) enables combining labels for training, combining disparate datasets, and hiding 
certain labels for training.

This example demonstrates consolidating two disparate Datasets. Two Dataset versions use `car` (lower case "c"), but a 
third uses `Car` (upper case "C"). 
The example maps `Car` (upper case "C") to `car` (lower case "c").

```python
# Create a Dataview object for an iterator that randomly returns frames according to queries 
myDataView = DataView(iteration_order=IterationOrder.random, iteration_infinite=True)

# The 1st Dataset (version) - "car" with lowercase "c"
myDataView.add_query(dataset_name='myDataset', version_name='myVersion' roi_query='car')

# The 2nd Dataset (version) - "car" with lowercase "c"
myDataView.add_query(dataset_name='dataset_2', version_name='aVersion',  
                     roi_query='car')

# A 3rd Dataset (version) - "Car" with uppercase "C"
myDataView.add_query(dataset_name='dataset_3', version_name='training', 
                     roi_query='Car')

# Use a mapping rule to translate "Car" (uppercase) to "car" (lowercase)
myDataView.add_mapping_rule(dataset_name='dataset_3',
                            version_name='training', 
                            from_labels=['Car'], 
                            to_label='car')
```

### Setting Label Enumeration Values

Set label enumeration values to maintain data conformity across multiple codebases and datasets. 
It is important to set enumeration values for all labels of importance. 
The default value for labels that are not assigned values is `-1`.

To assign enumeration values for labels use the [`DataView.set_labels`](google.com) method, set a mapping of a label 
(string) to an integer for ROI labels in a Dataview object.

If certain ROI labels are [mapped](#mapping-roi-labels) from certain labels **to** other labels, 
then use the labels you map **to** when setting enumeration values. 
For example, if the labels `truck`, `van`, and `car` are mapped **to** `vehicle`, then set enumeration for `vehicle`. 

```python
# Create a Dataview object for an iterator that randomly returns frames according to queries
myDataView = DataView(iteration_order=IterationOrder.random, iteration_infinite=True)

# Add a query for a Dataset version 
myDataView.add_query(dataset_name='myDataset', version_name='myVersion', 
                     roi_query='cat')

myDataView.add_query(dataset_name='myDataset', version_name='myVersion', 
                     roi_query='dog')

myDataView.add_query(dataset_name='myDataset', version_name='myVersion', 
                     roi_query='bird')

myDataView.add_query(dataset_name='myDataset', version_name='myVersion', 
                     roi_query='sheep')

myDataView.add_query(dataset_name='myDataset', version_name='myVersion', 
                     roi_query='cow')

# Set the enumeration label values
myDataView.set_labels({"cat": 1, "dog": 2, "bird": 3, "sheep": 4, "cow": 5, "ignore": -1,})
```