The Polygon Tool is used for high-precision instance and semantic segmentation. It allows for the annotation of complex or irregular shapes that cannot be accurately captured by standard bounding boxes.
Tool Selection: The Polygon Tool is selected via the Smart Tool Palette.
Efficiency (Tool Persistence): To speed up the workflow, the last selected tool remains active by default. There is no need to re-select the Polygon Tool after completing a shape; the user can immediately begin drawing the next object.
Closing a Shape: A polygon can be finalized in two ways:
Clicking back on the starting point (the first node).
Pressing the Enter key to automatically close the shape from the last point to the first.
When the Polygon Tool is active, the Interactive Toolbar provides four specialized modes to handle overlapping shapes and complex geometries. These modes allow users to manage how new polygons interact with existing ones:
Overwrite: The default mode. New polygons are drawn independently, regardless of existing annotations.
Subtract: Used to cut out a section from an existing polygon. This is ideal for creating “holes” or removing specific parts from a larger shape (e.g., labeling a donut shape).
Auto Subtract: A smart mode that automatically trims the new polygon so it does not overlap with existing shapes, ensuring perfectly aligned boundaries without manual effort.
Union: Allows for the merging of two or more polygons. When used, the new shape is combined with a selected existing polygon to form a single, unified logical entity.
The tool is optimized for high-speed vertex placement. Whether defining a simple triangle or a complex 100-point boundary, the canvas remains responsive, allowing for professional-grade segmentation at scale.
