What is Image Annotation?

Image annotation is the process of associating an entire image, or a section of an image, with an identifier label. Utilizing our proprietary platform and image annotation tools, Lionbridge AI provides various image annotation services that will match your project’s needs, including bounding boxes, 3D cuboids, lines and splines, semantic segmentation, pixel-precise/pixel-wise segmentation, polygons, image classification, and more.

Train your autonomous vehicles, drones, and other computer vision solutions to interpret images and video using high-quality annotated data. Focus on project development and execution while our crowd of curated experts get to work tagging key objects in images using the annotation method of your choice. When you order image annotation with Lionbridge, our team will source, annotate, and prepare the images with metadata in the file formats of your choice. Offload your image annotation tasks to Lionbridge and let us provide the ground truth for your algorithm under your strict requirements.

Our Image Annotation Platform


Whether you’re looking for high-quality image data to train your model, a platform to annotate your image data, or a team of expert annotators to tag your image data for you, our service is designed to meet your needs.

  • 500,000+ Contributors
  • 300+ Languages
  • 20+ Years of experience


Thanks to our rigorous, multi-tiered testing system, Lionbridge only offers positions to the top 3% of our tens of thousands of yearly applicants. Once accepted, our workers undergo regular performance evaluations to ensure we have the best people working on your project.


With crowdsourced image annotation and a streamlined project management platform, we can handle projects of varying complexity and at scale.

Customizable Workflows

Need things done in a specific way and under strict guidelines? We can work with you to create a tailored execution plan, ensuring that our team of experts completes your project according to your specific timeline and requirements.


Our Image Annotation Services

2D Bounding Boxes

Let our expert annotators draw and label 2D bounding boxes around the objects of interest in your images. Improve object detection in autonomous vehicles, drones, and more with our precise bounding box annotation services.

3D Bounding Boxes / Cuboids

3D cuboid annotation requires annotators to draw boxes around images to depict length, width, and approximate depth. Use our 3D cuboid annotation services to train object recognition in autonomous vehicles, augmented reality models, and other computer vision solutions.

Semantic Segmentation

Separate every pixel of an image into the segments you need your computer vision algorithm to recognize. Using our proprietary platform and tools, our annotators meticulously annotate every object in your images with pixel perfect accuracy.

Landmark Annotation

Label anatomical or structural points of interest in your images using landmark annotation. We provide keypoint annotation in human faces for facial recognition and emotion detection. We also provide pose-point annotation for human figure detection and movement prediction.


Annotate your images with pixel perfect polygons accurately drawn around objects of interest. Useful for training object localization and detection algorithms, polygon annotation is well suited for annotating objects with irregular shapes, like street signs in traffic images or houses in aerial imagery.

Image Categorization

Provide your computer vision models with a solid ground truth using accurately classified images. We employ an image classification workflow that ensures accuracy while eliminating annotator bias and human error. Our expert crowd will classify your images into your requested categories and our project managers will assess the quality of the data before sending you the final product.

How does Image Annotation with Lionbridge work?

how to crowdsource data

1. Project set-up

Our team will work with you to develop a custom solution based on your project objectives and timeline.

how to crowdsource data
how to crowdsource data

2. Production

Our crowd of multilingual experts get to work creating, annotating or validating your data.

how to crowdsource data
how to crowdsource data

3. Delivery

Our project management team checks, packages, and formats the data before being sent to you for final approval.

how to crowdsource data

Success Stories


Image Annotation Pricing

Wondering how much image annotation costs? The Lionbridge platform streamlines much of the process, allowing us to offer the most cost-effective image annotation solutions in the industry. Contact us to get a free estimate for your project.

  • Account Manager
  • Project Management
  • 24/7 Support
  • API
  • NDA
  • Volume pricing
  • Custom reporting
  • Enterprise-grade SLAs
  • Custom invoicing
  • Consulting services
Get in touch with our team today

Multilingual Image Annotation Services

Need image labelling done in a specific language?Lionbridge provides professional image annotation services in over 300 languages. Some of our most popular languages include:

  • Chinese image annotation
  • Dutch image annotation
  • French image annotation
  • German image annotation
  • Italian image annotation
  • Japanese image annotation
  • Portuguese image annotation
  • Spanish image annotation

Learn more about Image Annotation

Vahan Petrosyan is the co-founder of image annotation startup SuperAnnotate. In a conversation with us, he discussed recent developments in image annotation and how they will affect the demand for AI training data.
Wondering which image annotation types best suit your project? In this article, we introduce five types of image annotation and some of their applications.