Polyline

Updated 1 week ago by Alex Cota

Overview

Polyline annotations are continuous lines made of one or more line segments. The entire line is treated as one object. Polylines are typically used to annotate open shapes, since they don’t have to be closed like polygons do. This tool is often used to label shapes like road lane marks or other similar shapes.

Configuring polyline

Nested classifications

Any existing classification tools can be nested within the tool to capture metadata about the label. The example below demonstrates how to nest a single-choice radio question within a polyline object.

Creating instances

Steps for creating multiple instances of the same object for polyline tasks:

From the labeling interface, you can use the same class for more than one annotation. For example, if there are three tree branches in an image and you would like to assign the "tree branch" class to all three, you can create multiple instances of the "tree branch" class.

Follow these steps to create multiple instances of the same object:

  1. Select a class and draw the object.
  2. Select the same class again.
  3. Draw the next instance of the object.

Label format

Polyline labels can be imported as an existing label or a model prediction. They can also be exported in JSON format. The coordinates in the geometric key are in the clockwise direction.

"Label": { 
"classifications": [],
"objects": [
{
"line": [
{
"x": 2944.404,
"y": 1040.079
},
{
"x": 2839.546,
"y": 1071.253
},
{
"x": 2720.518,
"y": 1011.739
}
],
"color": "#2A00FF",
"featureId": "ck2mh6n9y000d0q6zr94pnsga",
"schemaId": "ck2mh4pcqznrb08425o8fbtaq",
"title": "Branch",
"value": "branch"
}
]
}


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