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CVAT Analytics and QA in Cloud

Analytics and quality assessment in CVAT Cloud

1 - Automated QA, Review & Honeypot

Guidelines for assessing annotation quality in CVAT automatically

In CVAT, it’s possible to evaluate the quality of annotation through the creation of a Ground truth job, referred to as a Honeypot. To estimate the task quality, CVAT compares all other jobs in the task against the established Ground truth job, and calculates annotation quality based on this comparison.

Note that quality estimation only supports 2d tasks. It supports all the annotation types except 2d cuboids.

Note that tracks are considered separate shapes and compared on a per-frame basis with other tracks and shapes.


Ground truth job

A Ground truth job is a way to tell CVAT where to store and get the “correct” annotations for task quality estimation.

To estimate task quality, you need to create a Ground truth job in the task, and annotate it. You don’t need to annotate the whole dataset twice, the annotation quality of a small part of the data shows the quality of annotation for the whole dataset.

For the quality assurance to function correctly, the Ground truth job must have a small portion of the task frames and the frames must be chosen randomly. Depending on the dataset size and task complexity, 5-15% of the data is typically good enough for quality estimation, while keeping extra annotation overhead acceptable.

For example, in a typical task with 2000 frames, selecting just 5%, which is 100 extra frames to annotate, is enough to estimate the annotation quality. If the task contains only 30 frames, it’s advisable to select 8-10 frames, which is about 30%.

It is more than 15% but in the case of smaller datasets, we need more samples to estimate quality reliably.

To create a Ground truth job, do the following:

  1. Create a task, and open the task page.

  2. Click +.

    Create job

  3. In the Add new job window, fill in the following fields:

    Add new job

    • Job type: Use the default parameter Ground truth.
    • Frame selection method: Use the default parameter Random.
    • Quantity %: Set the desired percentage of frames for the Ground truth job.
      Note that when you use Quantity %, the Frames field will be autofilled.
    • Frame count: Set the desired number of frames for the “ground truth” job.
      Note that when you use Frames, the Quantity % field will be will be autofilled.
    • Seed: (Optional) If you need to make the random selection reproducible, specify this number. It can be any integer number, the same value will yield the same random selection (given that the frame number is unchanged).
      Note that if you want to use a custom frame sequence, you can do this using the server API instead, see Jobs API #create.
  4. Click Submit.

  5. Annotate frames, save your work.

  6. Change the status of the job to Completed.

  7. Change Stage to Accepted.

The Ground truth job will appear in the jobs list.

Add new job

Managing Ground Truth jobs: Import, Export, and Deletion

Annotations from Ground truth jobs are not included in the dataset export, they also cannot be imported during task annotations import or with automatic annotation for the task.

Import, export, and delete options are available from the job’s menu.

Add new job


If you want to import annotations into the Ground truth job, do the following.

  1. Open the task, and find the Ground truth job in the jobs list.
  2. Click on three dots to open the menu.
  3. From the menu, select Import annotations.
  4. Select import format, and select file.
  5. Click OK.

Note that if there are imported annotations for the frames that exist in the task, but are not included in the Ground truth job, they will be ignored. This way, you don’t need to worry about “cleaning up” your Ground truth annotations for the whole dataset before importing them. Importing annotations for the frames that are not known in the task still raises errors.


To export annotations from the Ground truth job, do the following.

  1. Open the task, and find a job in the jobs list.
  2. Click on three dots to open the menu.
  3. From the menu, select Export annotations.


To delete the Ground truth job, do the following.

  1. Open the task, and find the Ground truth job in the jobs list.
  2. Click on three dots to open the menu.
  3. From the menu, select Delete.

Assessing data quality with Ground truth jobs

Once you’ve established the Ground truth job, proceed to annotate the dataset.

CVAT will begin the quality comparison between the annotated task and the Ground truth job in this task once it is finished (on the acceptance stage and in the completed state).

Note that the process of quality calculation may take up to several hours, depending on the amount of data and labeled objects, and is not updated immediately after task updates.

To view results go to the Task > Actions > View analytics> Performance tab.

Add new job

Quality data

The Analytics page has the following fields:

Field Description
Mean annotation quality Displays the average quality of annotations, which includes: the count of accurate annotations, total task annotations, ground truth annotations, accuracy rate, precision rate, and recall rate.
GT Conflicts Conflicts identified during quality assessment, including extra or missing annotations. Mouse over the ? icon for a detailed conflict report on your dataset.
Issues Number of opened issues. If no issues were reported, will show 0.
Quality report Quality report in JSON format.
Ground truth job data “Information about ground truth job, including date, time, and number of issues.
List of jobs List of all the jobs in the task

Annotation quality settings

If you need to tweak some aspects of comparisons, you can do this from the Annotation Quality Settings menu.

You can configure what overlap should be considered low or how annotations must be compared.

The updated settings will take effect on the next quality update.

To open Annotation Quality Settings, find Quality report and on the right side of it, click on three dots.

The following window will open. Hover over the ? marks to understand what each field represents.

Add new job

Annotation quality settings have the following parameters:

Field Description
Min overlap threshold Min overlap threshold(IoU) is used for the distinction between matched / unmatched shapes.
Low overlap threshold Low overlap threshold is used for the distinction between strong/weak (low overlap) matches.
OKS Sigma IoU threshold for points. The percent of the box area, used as the radius of the circle around the GT point, where the checked point is expected to be.
Relative thickness (frame side %) Thickness of polylines, relative to the (image area) ^ 0.5. The distance to the boundary around the GT line inside of which the checked line points should be.
Check orientation Indicates that polylines have direction.
Min similarity gain (%) The minimal gain in the GT IoU between the given and reversed line directions to consider the line inverted. Only useful with the Check orientation parameter.
Compare groups Enables or disables annotation group checks.
Min group match threshold Minimal IoU for groups to be considered matching, used when the Compare groups are enabled.
Check object visibility Check for partially-covered annotations. Masks and polygons will be compared to each other.
Min visibility threshold Minimal visible area percent of the spatial annotations (polygons, masks). For reporting covered annotations, useful with the Check object visibility option.
Match only visible parts Use only the visible part of the masks and polygons in comparisons.

GT conflicts in the CVAT interface

To see GT Conflicts in the CVAT interface, go to Review > Issues > Show ground truth annotations and conflicts.

GT conflict

The ground truth (GT) annotation is depicted as a dotted-line box with an associated label.

Upon hovering over an issue on the right-side panel with your mouse, the corresponding GT Annotation gets highlighted.

Use arrows in the Issue toolbar to move between GT conflicts.

To create an issue related to the conflict, right-click on the bounding box and from the menu select the type of issue you want to create.

GT conflict

Annotation quality & Honeypot video tutorial

This video demonstrates the process:

2 - Manual QA and Review

Guidelines on evaluating annotation quality in CVAT manually

In the demanding process of annotation, ensuring accuracy is paramount.

CVAT introduces a specialized Review mode, designed to streamline the validation of annotations by pinpointing errors or discrepancies in annotation.

Note: The Review mode is not applicable for 3D tasks.


Review and report issues: review only mode

Review mode is a user interface (UI) setting where a specialized Issue tool is available. This tool allows you to identify and describe issues with objects or areas within the frame.

Note: While in review mode, all other tools will be hidden.

Review mode screen looks like the following:

Review mode screen

Assigning reviewer

Note: Reviewers can be assigned by project or task owner, assignee, and maintainer.

To assign a reviewer to the job, do the following:

  1. Log in to the Owner or Maintainer account.

  2. (Optional) If the person you wish to assign as a reviewer is not a member of Organization, you need to Invite this person to the Organization.

  3. Click on the Assignee field and select the reviewer.

  4. From the Stage drop-down list, select Validation.

    Assigning reviewer

Reporting issues

To report an issue, do the following:

  1. Log in to the reviewer’s account.

  2. On the Controls sidebar, click Open and issue ().

  3. Click on the area of the frame where the issue is occurring, and the Issue report popup will appear.

    Issue report window

  4. In the text field of the Issue report popup, enter the issue description.

  5. Click Submit.

Quick issue

The Quick issue function streamlines the review process. It allows reviewers to efficiently select from a list of previously created issues or add a new one, facilitating a faster and more organized review.

Quick issue

To create a Quick issue do the following:

  1. Right-click on the area of the frame where the issue is occurring.

  2. From the popup menu select one of the following:

    • Open an issue…: to create new issue.
    • Quick issue: incorrect position: to report incorrect position of the label.
    • Quick issue: incorrect attribute: to report incorrect attribute of the label.
    • Quick issue…: to open the list of issues that were reported by you before.

Assigning corrector

Note: Only project owners and maintainers can assign reviewers.

To assign a corrector to the job, do the following:

  1. Log in to the Owner or Maintainer account.

  2. (Optional) If the person you wish to assign as a corrector is not a member of Organization, you need to Invite this person to the Organization.

  3. Click on the Assignee field and select the reviewer.

  4. From the Stage drop-down list, select Annotation.

    Assigning corrector

Correcting reported issues

To correct the reported issue, do the following:

  1. Log in to the corrector account.

  2. Go to the reviewed job and open it.

  3. Click on the issue report, to see details of what needs to be corrected.

    Issue report label

  4. Correct annotation.

  5. Add a comment to the issue report and click Resolve.

    Issue report

  6. After all issues are fixed save work, go to the Menu select the Change the job state and change state to Complete.

    Change job status

Review and report issues: review and correct mode

The person, assigned as assigned as reviewer can switch to correction mode and correct all annotation issues.

To correct annotation issues as a reviewer, do the following:

  1. Log in to the reviewer account.

  2. Go to the assigned job and open it.

  3. In the top right corner, from the drop-down list, select Standard.

    Change job status

Issues navigation and interface

This section describes navigation, interface and comments section.

Issues tab

The created issue will appear on the Objects sidebar, in the Issues tab.

It has has the following elements:

Element Description
Arrows You can switch between issues by clicking on arrows
Hide all issues Click on the eye icon to hide all issues
Hide resolved issues Click on the check mark to hide only resolved issues
Ground truth Show ground truth annotations and objects

Issues workspace

In the workspace, you can click on the issue, and add a comment on the issue, remove (Remove) it, or resolve (Resolve) it.

To reopen the resolved issue, click Reopen.

You can easily access multiple issues created in one location by hovering over an issue and scrolling the mouse wheel.

Issues comments

You can add as many comments as needed to the issue.

In the Objects toolbar, only the first and last comments will be displayed

You can copy and paste comments text.

Manual QA complete video tutorial

This video demonstrates the process:

3 - CVAT Team Performance & Monitoring

How to monitor team activity and performance in CVAT

In CVAT Cloud, you can track a variety of metrics reflecting the team’s productivity and the pace of annotation with the Performance feature.


Performance dashboard

To open the Performance dashboard, do the following:

  1. In the top menu click on Projects/ Tasks/ Jobs.
  2. Select an item from the list, and click on three dots (Open menu).
  3. From the menu, select View analytics > Performance tab.

Open menu

The following dashboard will open:

Open menu

The Performance dashboard has the following elements:

Element Description
Analytics for Object/ Task/ Job number.
Created Time when the dashboard was updated last time.
Objects Graph, showing the number of annotated, updated, and deleted objects by day.
Annotation speed (objects per hour) Number of objects annotated per hour.
Time A drop-down list with various periods for the graph. Currently affects only the histogram data.
Annotation time (hours) Shows for how long the Project/Task/Job is in In progress state.
Total objects count Shows the total objects count in the task. Interpolated objects are counted.
Total annotation speed (objects per hour) Shows the annotation speed in the Project/Task/Job. Interpolated objects are counted.

You can rearrange elements of the dashboard by dragging and dropping each of them.

Performance video tutorial

This video demonstrates the process: