Choosing the right label type for your image annotation project is important. Classification tags will maximize your labeling productivity, while polygons will boost your AI performance and bounding boxes may be for some an acceptable compromise.
Good news, check the Auto polygons tool which creates a polygon by simply adding a bounding box.
LabelFlow supports the following labeling types:
Image classification
Bounding boxes
Polygons
Auto polygons (a polygon generated from a bounding box)
You can read more about the different label types on our dedicated post:
The classification label type is the simplest and quickest way to label images. As opposed to the bounding box and polygon label types, the classification type doesn't have an associated geometry within the image. This label type simply consists of a general label for the entire image.
These are the simple steps you need to take to make a classification label:
Select the small arrow on the drawing tool on the left and select the classification tool
Click on the label box in the top left of the image or right-click on the image to select/add its class
It's that easy!
Check out the shortcuts page to find out how to increase your productivity!
A bounding box is the simplest type of label that is defined by just two points.
These are the simple steps you need to take to make a bounding box label:
Select the bounding box tool on the left
Click on the outermost edge of the subject of the label
Click the opposite edge of the object to create a rectangle covering the subject
Right-click on the label to select/add its class
You can move and resize the bounding box to make changes after it is created
Select and drag a vertex to its correct position
Click anywhere in the label to drag it to the correct position
The polygon label type is defined by several vertices, which allows the user to accurately label complex shapes.
By definition, polygon labels are closer in shape to the subject of the label than a simple bounding box.
These are the simple steps you need to take to make a polygon label:
Select the small arrow on the drawing tool on the left and select the polygon tool
Click on the outermost edge of the subject of the label
Follow the edges of the subject and select the vertices of the polygon
When you are finished click on the vertex near the pointer and the polygon will be created
Right-click on the label to select/add its class
You can create vertices and move existing ones to change the shape and size of the polygon!
Add vertices to the polygon by selecting an edge and dragging the vertex that appears
Select and drag an existing vertex to move it
The Auto polygon tool allows you to boost your labeling productivity.
You create a bounding box around the object you wish to label and an AI automatically transforms this bounding box into a precise polygon around your object.
Click on the polygon you want to edit
You can now drag any points on the contour to adjust the polygon geometry
This edition mode is also illustrated in the above video.
You can refine the automatically generated polygons by simply moving the target keypoint and/or adding inside keypoints and outside keypoints .
This is as simple as moving the target keypoint and/or doing a click inside or outside the created polygon.
Target keypoint. It must always be on the object you wish to label. Else move it on the object.
Outside keypoint. A click inside the polygon will add an outside keypoint and exclude this area from the polygon label.
Inside keypoint. A click outside the polygon will add an inside keypoint and include this area to the polygon label.
Always start by moving the target keypoint to another position on the object if the generated polygon is not good enough. Only after adjusting the target keypoint should you start adding inside and outside keypoints.
Click on to activate the selection mode (or press v for the shortcut)
Select the polygon edition mode (next to the class selection menu in the top left). You can press e to switch between both edition modes.
