CVAT Annotation Interface

• 1: Navigation bar & Menu
• 2: Controls sidebar
• 3: Objects sidebar
• 4: CVAT Workspace

1 - Navigation bar & Menu

The navigation panel and drop-down Menu, allow you to switch between frames, change the annotation mode, save your work, and more.

See:

• Menu
• Navigation bar
  • Save, Undo, Done
  • Navigation controls
• Job information and Annotation Mode switcher

Menu

Use the Menu options to upload and download annotations, change the status of the job, and access other features listed in the table below:

Panel Item	Description
Upload annotations	Upload annotations into a task.
Export as a dataset	Download a dataset in one of the supported formats.
Remove annotations	Delete all annotations for the current job. Use Select range to remove annotations for a specific range of frames. Enable the Delete only keyframe for tracks checkbox to delete only keyframes from the tracks within the selected range.
Run actions	Run annotation actions on the annotated dataset. Annotations action is a feature that allows you to modify a bulk of annotations on many frames. It supports only shape objects.
Open the task	Opens a page with details about the task.
Change job state	Changes the state of the job: New: The job is newly created and has not been started yet. It is waiting for annotation work to begin. In Progress: The job is currently being worked on. Annotations are being added or edited. Rejected: The job has been reviewed and deemed unsatisfactory or incorrect. It requires revisions and further work. Completed: The job has been finished, reviewed, and approved. No further changes are necessary.
Finish the job	Saves annotations and sets job state to Completed.

Navigation bar

Use the navigation bar to save annotation results, switch between frames, and access other features listed in the tables below.

Save, Undo, Done

Use the following buttons, to save your work, undo changes, and move tasks to done.

Function	Description
Save work	Saves annotations for the current job. The button indicates the saving process.
Undo/Redo	Use buttons to undo actions or redo them.
Done	Used to complete the creation of the object. This button appears only when the object is being created.
Block	Used to pause automatic line creation when drawing a polygon with OpenCV Intelligent scissors. Also used to postpone server requests when creating an object using AI Tools.

Navigation controls

Overview of how to navigate through frames within the interface, with detailed descriptions provided in the table below.

Function	Description
Go to the first/last frame	Navigate to the first or the last frame of the sequence.
Go back with a step/Go next with a step	Move to the previous or next frame by a predefined step. Shortcuts: C — previous frame. V — next frame. Default step size is 10 frames. To modify this, navigate to Nickname > Settings > Player Step.
Go back/Go next	Navigate to the neighboring frames. Shortcuts: D — previous frame. F — next frame. Go back/Go next buttons are customizable: To customize, right-click on the button and select one of three options (left to right): The default setting moves to the next or previous frame (step size is 1 frame). Move to the next or previous frame that contains objects (e.g., filtered). For more information, refer to Filters. Move to the next or previous frame without annotations. Use this option to quickly locate missed frames. .
Play/Pause	Switch between playing and pausing the sequence of frames or set of images. Shortcut: Space. To adjust the playback speed, go to Nickname > Settings > Player Speed.
Go to the specific frame	Enter the number of the frame you want to go to and press Enter.
Delete frame	Click to delete current frame.

Job information and Annotation Mode switcher

This section outlines various functionalities, including how to switch to the fullscreen player mode, access job information, and use the Workspace Switcher to toggle between different annotation and QA modes.

Function	Description
Fullscreen	The fullscreen player mode. The keyboard shortcut is F11.
Info	Open the job info. Overview: Assignee - the individual to whom the job is assigned. Reviewer– the user tasked with conducting the review. For more information, see Manual QA Start frame - the number of the first frame in this job. Stop frame - the number of the last frame in this job. Frames - the total number of frames in the job. Annotations Statistics table displays the number of created shapes, categorized by labels (e.g., vehicle, person) and the type of annotation (shape, track), as well as the count of manual and interpolated frames.
Filters	Switches on Filters.
Workplace Switcher	The drop-down list to switch between different annotation modes: Overview: Standard – default mode. Attribute – annotation with Attributes Single Shape – Single shape annotation mode. Tag annotation- annotation with Tags Review – Manual QA mode.

2 - Controls sidebar

Navigation

Navigation block - contains tools for moving and rotating images.

Icon	Description
	Cursor (Esc)- a basic annotation editing tool.
	Move the image- a tool for moving around the image without the possibility of editing.
	Rotate- two buttons to rotate the current frame a clockwise (Ctrl+R) and anticlockwise (Ctrl+Shift+R). You can enable Rotate all images in the settings to rotate all the images in the job

Zoom

Zoom block - contains tools for image zoom.

Icon	Description
	Fit image- fits image into the workspace size. Shortcut - double click on an image
	Select a region of interest- zooms in on a selected region. You can use this tool to quickly zoom in on a specific part of the frame.

Shapes

Shapes block - contains all the tools for creating shapes.

Icon	Description	Links to section
	AI Tools	AI Tools
	OpenCV	OpenCV
	Rectangle	Shape mode; Track mode; Drawing by 4 points
	Polygon	Annotation with polygons; Track mode with polygons
	Polyline	Annotation with polylines
	Points	Annotation with points
	Ellipses	Annotation with ellipses
	Cuboid	Annotation with cuboids
	Brushing tools	Annotation with brushing
	Tag	Annotation with tags
	Open an issue	Review (available only in review mode)

Edit

Edit block - contains tools for editing tracks and shapes.

Icon	Description	Links to section
	Merge Shapes(M) - starts/stops the merging shapes mode.	Track mode (basics)
	Group Shapes (G) - starts/stops the grouping shapes mode.	Shape grouping
	Split - splits a track.	Track mode (advanced)
	Split - splits a track.	Track mode (advanced)
	Joins multiple labels into one	Joining mask tool
	Slices one label into several.	Slice mask/polygon

Move image

Switching between user interface modes.

1. Use arrows below to move to the next/previous frame. Use the scroll bar slider to scroll through frames. Almost every button has a shortcut. To get a hint about a shortcut, just move your mouse pointer over an UI element.

2. To navigate the image, use the button on the controls sidebar. Another way an image can be moved/shifted is by holding the left mouse button inside an area without annotated objects. If the Mouse Wheel is pressed, then all annotated objects are ignored. Otherwise the a highlighted bounding box will be moved instead of the image itself.

   

3. You can use the button on the sidebar controls to zoom on a region of interest. Use the button Fit the image to fit the image in the workspace. You can also use the mouse wheel to scale the image (the image will be zoomed relatively to your current cursor position).

   

3 - Objects sidebar

In the objects sidebar, you can see the list of available objects on the current frame. The following figure is an example of how the list might look like:

Shape mode	Track mode

Objects properties

Filter input box

The way how to use filters is described in the advanced guide here.

List of objects

• Switch lock property for all - switches lock property of all objects in the frame.
• Switch hidden property for all - switches hide the property of all objects in the frame.
• Expand/collapse all - collapses/expands the details field of all objects in the frame.
• Sorting - sort the list of objects: updated time, ID - accent, ID - descent

Objects on the sidebar

The type of shape can be changed by selecting the Label property. For instance, it can look like shown in the figure below:

Object action menu

The action menu calls up the button:

The action menu contains:

• Create object URL - puts a link to an object on the clipboard. After you open the link, this object will be filtered.

• Make a copy - copies an object. The keyboard shortcut is Ctrl + C > Ctrl + V.

• Propagate function copies the form to multiple frames and displays a dialog box where you can specify the number of copies or the frame to which you want to copy the object. The keyboard shortcut is Ctrl + B. On how to propagate only filtered shapes, see Shapes converter
  There are two options available:

  • Propagate forward () creates a copy of the object on N subsequent frames at the same position.
  • Propagate backward () creates a copy of the object on N previous frames at the same position.

  

• To background - moves the object to the background. The keyboard shortcut - or _

• To foreground - moves the object to the foreground. The keyboard shortcut + or =

• Change instance color- choosing a color using the color picker (available only in instance mode).

  

• Remove - removes the object. The keyboard shortcut Del, Shift+Del.

A shape can be locked to prevent its modification or moving by an accident. Shortcut to lock an object: L.

A shape can be Occluded. Shortcut: Q. Such shapes have dashed boundaries.

You can change the way an object is displayed on a frame (show or hide).

Switch pinned property - when enabled, a shape cannot be moved by dragging or dropping.

**Tracker switcher **- enable/disable tracking for the object.

By clicking on the Details button you can collapse or expand the field with all the attributes of the object.

Labels

In this tab, you can lock or hide objects of a certain label. To change the color for a specific label, you need to go to the task page and select the color by clicking the edit button, this way you will change the label color for all jobs in the task.

Fast label change

You can change the label of an object using hotkeys. In order to do it, you need to assign a number (from 0 to 9) to labels. By default numbers 1,2…0 are assigned to the first ten labels. To assign a number, click on the button placed at the right of a label name on the sidebar.

After that, you will be able to assign a corresponding label to an object by hovering your mouse cursor over it and pressing Ctrl + Num(0..9).

In case you do not point the cursor to the object, pressing Ctrl + Num(0..9) will set a chosen label as default, so that the next object you create (use the N key) will automatically have this label assigned.

Appearance

Color By options

Change the color scheme of the annotation:

• Instance — every shape has a random color

  

• Group — every group of shape has its own random color, ungrouped shapes are white

  

• Label — every label (e.g. car, person) has its own random color

  

  You can change any random color pointing to a needed box on a frame or on an object sidebar.

Fill Opacity slider

Change the opacity of every shape in the annotation.

Selected Fill Opacity slider

Change the opacity of the selected object’s fill. It is possible to change the opacity while drawing an object in the case of rectangles, polygons, and cuboids.

Outlines borders checkbox

You can change a special shape border color by clicking on the Eyedropper icon.

Show bitmap checkbox

If enabled all shapes are displayed in white and the background is black.

Show projections checkbox

Enables/disables the display of auxiliary perspective lines. Only relevant for cuboids

Hide objects sidebar

Hide - the button hides the object’s sidebar.

4 - CVAT Workspace

In CVAT the Workspace serves as a work area where annotators interact with images, videos, and the various tools available to create high-quality annotations.

See:

• Image settings in CVAT
  • Adding grid overlay to image in CVAT
  • Changing color settings of image in CVAT
• Adding layers and Z-axis slider
• Interacting with Objects

Image settings in CVAT

The Image settings panel serves as a versatile tool for fine-tuning the visual aspects of your image. Whether you need to brighten the image, increase contrast, or make other adjustments, this panel is your go-to.

Additionally, the panel allows you to overlay a grid on the image for more precise annotation.

Note: Adjusting the image settings only alters how the pictures are displayed. The images themselves will remain unmodified and unchanged.

By default, the Image settings panel is not visible. To access it, click on the Arrow Up () icon located at the bottom of the workspace.

Adding grid overlay to image in CVAT

To add the grid to the image, do the following:

1. Open the Image Settings panel.
2. Locate and check the box that allows you to overlay a grid on the image.
3. Specify the grid cell size in square millimeters by entering the desired number in the Size field.
4. From the Color drop-down list, select the color of the grid.
5. Use the Opacity slider to change the transparency of the grid overlay.

Changing color settings of image in CVAT

To change the color setting of the image is CVAT, do the following:

1. Open the Image Settings panel.
2. Use the slider to change the color quality.

There are four color quality settings in CVAT:

Brightness increases and decreases the overall lightness of the image:

Contrast is the range of brightness, from lightest to darkest, in an image.

Saturation describes the intensity of the color.

Gamma correction can be used to control the overall brightness of an image

To reset the setting to default values, click Reset color settings

Adding layers and Z-axis slider

Z-axis Slider enables you to add annotation layers while hiding the layers positioned beyond.

You can also move between layers by moving the slider to the layer you need.

The slider becomes active when multiple Z-layers are present within a frame. Click + on the slider to add a new layer; upon pressing it, a new layer is automatically created and activated.

You can also relocate objects between layers using the + and - keys.

Interacting with Objects

The workspace is also equipped with the following features:

• Right-clicking an object opens the Object Card. This interface contains essential controls for modifying the object’s label and attributes, as well as providing access to an action menu.

  

• Right-clicking on a polygon point will open a menu, from which you can Delete point or Set start point.