Polygon

Label for Semantic & Instance Segmentation

Create a Polygon Label

  1. Navigate to the "Label Definitions" sub-tab of your project

  2. Type label name in the "Name" field

  3. Choose Polygon from the "Type" drop-down

  4. Select label color from the color chooser menu

  5. Click "Save" button

  6. Repeat as needed for multiple labels

When to use

Polygons enable semantic and instance segmentation.

Architectures such as FCN and Mask R-CNN support polygons (or pixel masks) as input. Common use cases include visually segmenting the road, pedestrians, and cars for automated vehicles.

Pixels categorized for person, bike, and road.

Adding Sublabels

This is useful for having classes associated with higher level instances. Example: drawing rectangles around birds for object detection, but having a class for types of bird within the rectangle (Duck, Geese, etc...).

  1. Click "Add Sublabel"

  2. Type a sublabel name

  3. Choose sublabel type

  4. Fill out label options

  5. Click "Save"

Data Format

A Polygon schema element creates an array of objects with data consisting of an array of vertices. Each vertex is a XY coordinate relative (0.0 to 1.0) to width and height respectively. The last point is repeated indicating the Polygon is closed.

[
0:{
"type":"polygon"
"data":{
"points":[
0:[
0:0.55
1:0.58
]
1:[
0:0.79
1:0.72
]
2:[
0:0.58
1:0.92
]
3:[
0:0.33
1:0.71
]
4:[
0:0.55
1:0.58
]
]
}
}
]