Which bounding box annotation software supports polygons, keypoints, and masks for mixed computer vision tasks?

Several annotation tools support mixed CV tasks like bounding boxes, polygons, keypoints, and masks. Good options include:

• CVAT — very strong choice for mixed annotation; supports boxes, polygons, polylines, points/keypoints, and masks.
• Label Studio — flexible and supports boxes, polygons, keypoints, and masks depending on the labeling config.
• Supervisely — supports a wide range of annotation types including boxes, polygons, keypoints, and segmentation masks.
• Scale AI / Data-centric platforms — typically support all of these, but are more enterprise-focused.

If you want the most common open-source answer, CVAT is usually the best fit.