Images

Encord provides comprehensive support for image annotation. With the image editor, you can:

Label using any annotation type such as bounding boxes, rotatable boxes, polygons, polylines, keypoints, and primitives.
Create frame-level & object classifications.
Object detection and instance segmentation.
Reduce manual annotations with automation (e.g., importing model predictions) features.

Task Management

Before we get into the details of the label editor and making annotations, a quick note about scheduling annotation work. Annotation is done in the annotation phase of the task management system. In order to ensure annotation work is saved properly, it's crucial that each labeling task is properly assigned to an annotator, annotators always access the task through the Queue tab in the Task Management System, and only the assigned annotator works on any given task at any given time.

Annotation types

Objects are annotated using bounding boxes, polygons, polylines, keypoints or primitives. Frames are annotated using classifications. Instantiating objects or classifications in the image editor generates a UUID that uniquely identifies that label in the frame.

Labels can be assigned with static classifications as defined in the specified ontology. Static classifications define the global properties of an object (e.g., the butterfly is of type red admiral and is orange).

You can read more about automation for image annotation here.

Bounding box

Creating a bounding box requires an ontology with a bounding box annotation type. Instantiate a new bounding box label by clicking on the specified class in the 'Classes' menu, or by using the specified hotkey (e.g., 1, 2, 3).

Bounding box labels can be assigned with static classifications should they be defined in your ontology:

Highlight an object by clicking on it in the editor canvas or by clicking on the Plus icon or start/end frame in the range overview for the specified bounding box
Assign a classifications by clicking on the relevant buttons or using the set hotkeys (e.g., q, u).

Rotatable box

Traditional bounding boxes are great for annotating objects that appear in horizontal or vertical orientation, however, their accuracy may be limited when it comes to annotating objects at an angle. In such cases, use rotatable boxes to produce more accurate annotations.

Creating a rotatable bounding box requires an ontology with a rotatable box annotation type.Instantiate a new rotatable box label by clicking on the specified class in the 'Classes' menu or using the specified hotkey. Resize rotatable boxes like normal bounding boxes, and then grab the rotation handle to adjust the position until you're satisfied with the annotation's accuracy, as below.

Rotatable boxes can be assigned static classifications should they be defined in your ontology,
and you can export the labels as usual.

Polygon

Polygons are often necessary if you want to train your applications on the tightest object boundaries. Creating a
polygon requires an ontology with a polygon annotation type. Enable or disable free-hand drawing mode by pressing d on your keyboard. Polygon coarseness for polygons drawn free-hand is set in the 'Settings' drawer in the Drawing settings drop-down. Instantiate a new polygon label by clicking on the specified class in the 'Classes' menu or using the specified hotkey (e.g., 1, 2, 3).

A polygon can be closed by double-clicking anywhere on the canvas. Doing so will "snap" creating an edge between the last vertex to the first vertex drawn.

Polygon labels can be assigned static classifications should they be defined in your ontology:

Highlight an object by clicking on it in the editor canvas or by clicking on the + icon or start/end frame in the range overview for the specified polygon
Assign a classifications by clicking on the relevant buttons or using the set hotkeys (e.g., q, u)

Here's an illustration of an image containing polygon and polyline objects.

Polyline

Creating a polyline requires an ontology with a polyline annotation type. Enable or disable free-hand drawing mode by pressing d on your keyboard. Polyline coarseness for polylines drawn free-hand is set in the 'Settings' drawer in the Drawing settings drop-down. Instantiate a new polyline label by clicking on the specified class in the 'Classes' menu or using the specified hotkey (e.g., 1, 2, 3).

When free-hand drawing is off, each click of the mouse will place a point of the polyline. A polyline requires a minimum of two points. Double-click anywhere on the canvas to finish drawing the polyline. Note however, that the location of the double-click does not create a point or affect the geometry of the polyline in any way. If you've only created one point prior to double-clicking, the polyline will not be created and your polyline about to be created will be canceled. Ensure you single-click at least twice to create at least two separate points, then double-click to finish drawing the polyline.

Polyline labels can be assigned with static classifications should they be defined in your ontology:

Highlight an object by clicking on it in the editor canvas or by clicking on the Plus icon or start/end frame in the range overview for the specified polyline
Assign a classification by clicking on the relevant buttons or using the set hotkeys (e.g., q, u)

Keypoint

Creating a keypoint requires an ontology with a keypoint annotation type. Instantiate a new keypoint label by clicking on the specified class in the 'Classes' menu or using the specified
hotkey (e.g., 1, 2, 3).

Keypoints labels can be assigned with static classifications should they be defined in your ontology:

Highlight an object by clicking on it in the editor canvas or by clicking on the Plus icon or start/end frame in the range overview for the specified keypoint
Assign classifications by clicking on the relevant buttons or using the set hotkeys (e.g., q, u)

Primitives

Creating a primitive (f.k.a. skeleton templates) requires an ontology with a primitive annotation
type. Use primitives to templatize shapes (e.g., 3D cuboids, pose estimation skeletons) commonly
used by your annotation team.

Instantiate a new primitive label by clicking on the specified class in the 'Classes' menu or using the specified hotkey (e.g., 1, 2, 3).

Object primitives allow you to define properties of edges defined in your template as visible, occluded, or invisible. Toggle the edge property settings for a primitive by highlighting the primitive and clicking the Show controls button.

Primitive labels can be assigned with static classifications should they be defined in your ontology:

Highlight an object by clicking on it in the editor canvas or by clicking on the Plus icon or start/end frame in the range overview for the specified primitive
Assign classifications by clicking on the relevant buttons or using the set hotkeys (e.g., q, u)

Watch the quick demo below to see how to use object primitives in the editor.

Segmentation masks / Bitmasks

Bitmasks allows you to create labels using a brush tool to select parts of an image. This can be useful when creating labels for vessel outlines, or labelling topologically separate regions belonging to the same frame classification.

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Note
Creating a mask segmentation requires an ontology with the Bitmask annotation type.

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Tip
Existing Bitmask labels can be updated using the brush tool, threshold brush, and eraser tools.

Brush tool

When you select your bitmask annotation type, the brush tool will be selected by default. You can adjust the size of the bitmask brush tool using the slider in the bitmask popup, as seen in the screenshot above.

The brush tool can be selected by clicking the icon, or by hitting f on your keyboard while the popup is open.

When your label is ready, click Apply label, or press Enter.

Threshold brush

The Threshold brush tool enables you to set an intensity value threshold for labels created using the bitmask annotation type. This means only parts of the image within the set intensity range will be labeled when selected using the Threshold brush tool.

To select the threshold brush, click the icon, or hit g on your keyboard while the popup is open. Adjust the size of the brush tool, as well as the range of intensity values you would like to include in your labels using the two sliders on the popup, as seen in the screenshot below.

Use the Threshold preview toggle to see which parts of an image correspond to your set threshold. This allows you to see which parts of the image will be labeled when covered by the Threshold brush tool.

When your label is ready, click Apply label, or press Enter.

Eraser

The Eraser tool allows you to erase parts, or the entirety of your Bitmask selection if the Apply label button has not been clicked yet.

To select the threshold brush, click the icon, or hit h on your keyboard while the popup is open.

Updating Bitmask labels

To update a bitmask label:

Click the Bitmask label you would like to edit.
Select either the brush, threshold brush, or eraser tool and make your changes.
Press Enter or click the button in the bitmask popup.

Frame classification

Creating frame classification(s) requires an ontology with a classification annotation type. Frame-level classifications consider the frame as a whole, not any given object's localization. Instantiate a frame-level classification label by clicking on the specified class in the 'Classes' menu or using the specified hotkey (e.g., 1, 2, 3).

Encord currently supports radio, checklist, and free-form text input classification types. Edit existing classification labels by clicking on the + icon for the specified label.

1. Create a frame classification from ontology 2. Edit a classification

Automation

Import model predictions

Encord's Python SDK & APIs allow you to import model predictions programmatically. Importing model predictions helps to pre-annotate your data to save annotation costs.

Automated labeling

Encord's Apollo allows you to build models for automated data labeling.

Please see our documentation on models here.