Image annotation refers to the process of labeling or tagging objects, regions, or specific features within an image. This is a key step in preparing data for machine learning tasks, particularly in supervised learning. The goal is to provide a model with labeled data so it can learn to recognize patterns or objects in unseen images. Common types of image annotation include: 1) Bounding Boxes, where a rectangle is drawn around an object of interest to highlight its location in the image. This is often used in object detection tasks. 2) Semantic Segmentation, where each pixel in the image is labeled with a class. This is useful in applications like autonomous driving, where the model needs to understand the boundaries of each object, such as roads, vehicles, and pedestrians. 3) Keypoint Annotation, where key facial features (e.g., eyes, nose, and mouth) or other points are marked for use in tasks like facial recognition or pose estimation. 4) Polygons, which involve drawing a shape around an object with more complex boundaries, typically used for more irregularly shaped objects in medical imaging or satellite image analysis. Annotation is essential for training machine learning models, especially in tasks like object detection, facial recognition, and segmentation. It can be done manually, using tools like LabelImg for bounding boxes, or with automated systems in more complex environments.
What is image annotation? What are its types?

- Master Video AI
- Mastering Audio AI
- Vector Database 101: Everything You Need to Know
- Information Retrieval 101
- Accelerated Vector Search
- All learn series →
Recommended AI Learn Series
VectorDB for GenAI Apps
Zilliz Cloud is a managed vector database perfect for building GenAI applications.
Try Zilliz Cloud for FreeKeep Reading
How does cloud computing reduce IT costs?
Cloud computing reduces IT costs primarily by eliminating the need for significant upfront investments in hardware and s
How are embeddings being used in edge AI?
Embeddings are increasingly being used in edge AI to enable fast, efficient, and localized processing of data on devices
What are episodic tasks in reinforcement learning?
Episodic tasks in reinforcement learning (RL) are tasks where the agent's interactions with the environment are divided