By clicking "Accept", you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. See our Privacy Policy for more information
How-to

Bounding Box annotation for Computer Vision models: 10 essential tips

Written by
Aïcha
Published on
2023-09-08
Reading time
0
min
🔎 Annotation of Bounding Boxes is essential in Machine learning, especially in areas such as Computer Vision.

This is the simplest annotation for creating datasets used to train these models. However, a precise annotation of Bounding Boxes is essential for training AI models that can detect and locate objects in images. In this article, we explore Ten best practices for ensuring annotations of Bounding Boxes High quality.

1. Bounding Box: The Importance of Choosing the Right Tools

The first step to successfully annotate bounding boxes is to select the appropriate tools. There are numerous annotation platforms and software available, such as Labelbox, Supervisely, Encord, V7 Labs gold Label Studio, which offers advanced features to help you get accurate results.

💡 For more information, do not hesitate to consult our Top 10 best performing data annotation platforms.

2. Develop clear and comprehensive instructions for image annotators

Before starting the annotation process, establish Clear and detailed guidelines For Your Annotators (or Data Labelers). These guidelines should include visual examples, specific instructions on how to draw Bounding Boxes, and rules for categorizing objects.

The annotation area should be clearly defined in a guide to avoid confusion, and it may be useful to refer to specific examples for Standardize the annotation approach through various projects. Understanding these elements can greatly influence the effectiveness of computer vision models by providing them with well-structured and accurate data, pixel by pixel.

3. Train Data Labelers in technical annotation (Bounding Box, Keypoints, Segmentation, etc.)

It is essential to Train Your Annotators On the fundamentals of the annotation of Bounding Boxes, as well as on the specificities of your project. Make sure they fully understand the goals of your task and the specific rules to follow. If you are working with a certified service provider, make sure it has a Training Path For its teams as well as regular follow-up.

Les Principles of managing annotations Should be designed and communicated in a uniform manner so as to facilitate the identification and separation of different elements within the same image. Data Labelers should have the same reflexes when using annotation rectangles to isolate and identify each object separately, to avoid too much variation in the annotated data set, by ensuring a precise delineation that takes into account each pixel.

This is a Bounding Box (source: CVAT.ai)

4. Label classes correctly

If Your Annotation task Involves of Classifying or Categorizing Objects, make sure that each Bounding Box Is associated with the appropriate class. Use a color coding or labeling system to distinguish between different classes (which is what most modern annotation tools allow today—if not, consider reviewing your Setup).

To ensure a Effective demarcation, it is also essential to consider latitude and longitude (in spatial annotation of satellite images for example), you should therefore prefer a tool that gives indications to Data Labelers to help them be as accurate as possible. The management of these coordinates must be integrated into the annotation platform for maximum precision. In addition, the width and height of the enclosing boxes must be adjusted carefully to avoid any deformation that could affect the accuracy of the training data.

5. Do Not Overlook the Annotation Interface and Its Contrast

Your Data Labeler team is called upon to work several hundred or thousands of hours on your data. If the Interface is not very intuitive or not very efficient, this will impact the quality of your data at the end of the process. And that (often) has nothing to do with the performance level of the annotators. Also, think about contrast : if you annotate invoices on a white background with 40 different labels, and each label is the same color (white or light colors), this will mislead the annotators, make the work more difficult for them... and of course generate errors.

Logo


Bounding Box Specialists, On-Demand
Speed up your data annotation tasks and reduce errors by up to 10 times. Start collaborating with our Data Labelers today.

6. Managing Ambiguous or Undocumented Cases

Set guidelines for Manage situations where the object to be annotated is partially visible, blurry, or hidden by another object. Annotators should be trained to identify and deal with these cases resulting... or simply ignore them to avoid creating false positives.

7. Avoid over-annotation

Pay attention to Do Not Annotate Empty Areas Or Not to Cover the Same Object with Several Bounding Boxes, which can lead to model errors.

8. Maintain proportions

Les Bounding Boxes Should maintain the correct proportions to accurately reflect the size of the object in pixels. Avoid deforming or stretching them. These Should Be at Most Close to the object for precise delimitation, ensuring that every pixel inside the bounding box is relevant to the target object.

9. Management of Partially Hidden or Ininconspicuous Objects

Clearly mark the parts of objects that are partially hidden or obscured by other objects, with comments or indications (meta-data) in your platform. This will allow models to Understanding the presence of occultation.

10. Quality control, documentation, and iteration

Set up a Verification and quality control process to review annotations and identify errors or inconsistencies. Verification is critical to ensure that your annotated data is accurate and reliable.

Also hold a Detailed record of each annotation family for future reference. Encourage annotators to provide feedback on challenges encountered while annotating. This iterative process can help improve data quality over the long term.


The annotation of surrounding boxes (Bounding Boxes) is an essential component in preparing data for machine learning models. Precise annotation makes it possible to correctly delineate the objects of interest in an image, thus offering critical information for the training of object detection models.

By following the ten best practices described in this article and integrating them into your annotation processes, you will be in a position to produce High quality annotations That will result in better and more accurate machine learning models.

Do you want to know more? To ensure optimal annotations, we remind you that it is important to focus on the coherence and precision of the surrounding boxes, ensuring that each box correctly covers the contours of the object. In addition, a good practice is to adapt the annotation criteria according to the specifics of the application: some applications require tighter margins, while others tolerate approximations.

If you are looking for expertise in data annotation and want to benefit from optimal quality for your AI projects, do not hesitate to contact Innovatiana. Our team of specialists is at your disposal to assist you in the production of precision annotations, adapted to the specific needs of your project!