Segment Anything Model and Dataset (SAM and SA-1B)

Introduction

Segment Anything is a project aimed at democratizing image segmentation by providing a foundation model and dataset for the task. Image segmentation involves identifying which pixels in an image belong to a specific object and is a core component of computer vision. This technology has a wide range of applications, from analyzing scientific imagery to editing photos. However, creating accurate segmentation models for specific tasks often necessitates specialized work by technical experts, access to AI training infrastructure, and large amounts of carefully annotated data.

Segment Anything Model (SAM) and SA-1B Dataset

On April 5, 2023, the Segment Anything project introduced the Segment Anything Model (SAM) and the Segment Anything 1-Billion mask dataset (SA-1B), as detailed in a research paper. The SA-1B dataset is the largest-ever segmentation dataset, and its release aims to enable various applications and further research into foundation models for computer vision. The SA-1B dataset is available for research purposes, and the Segment Anything Model is released under an open license (Apache 2.0).

SAM is designed to reduce the need for task-specific modeling expertise, training compute, and custom data annotation in image segmentation. Its goal is to create a foundation model for image segmentation that can be trained on diverse data and adapt to specific tasks, similar to the prompting used in natural language processing models. However, segmentation data required for training such a model is not readily available, unlike images, videos, and text. Consequently, the Segment Anything project set out to develop a general, promptable segmentation model and simultaneously create a segmentation dataset on an unprecedented scale.

SAM: A Generalized Approach to Segmentation

Historically, there have been two main approaches to segmentation problems: interactive segmentation and automatic segmentation. Interactive segmentation enables the segmentation of any object class but requires human guidance, while automatic segmentation is specific to predetermined object categories and requires substantial amounts of manually annotated data, compute resources, and technical expertise. SAM is a generalization of these two approaches, capable of performing both interactive and automatic segmentation.

Promptable Segmentation

SAM is designed to return a valid segmentation mask for any prompt, whether it be foreground/background points, a rough box or mask, freeform text, or any other information indicating what to segment in an image. This model has been trained on the SA-1B dataset, which consists of over 1 billion masks, allowing it to generalize to new objects and images beyond its training data. As a result, practitioners no longer need to collect their own segmentation data and fine-tune a model for their use case.

Segmenting 1 Billion Masks: Building SA-1B

To train SAM, a massive and diverse dataset was needed. The SA-1B dataset was collected using the model itself; annotators used SAM to annotate images interactively, and the newly annotated data was then used to update SAM. This process was repeated multiple times to iteratively improve both the model and the dataset.

A data engine was built for creating the SA-1B dataset, which has three gears:

1. model-assisted annotation,
2. a mix of fully automatic annotation, and assisted annotation.
3. fully automatic mask creation.

The final dataset includes more than 1.1 billion segmentation masks collected on about 11 million licensed and privacy-preserving images.

Potential Applications and Future Outlook

SAM has the potential to be used in a wide array of applications, such as AR/VR, content creation, scientific domains, and more general AI systems. Its promptable design enables flexible integration with other systems, and its composition allows it to be used in extensible ways, potentially accomplishing tasks unknown at the time of model design. In the future, SAM could be utilized in numerous domains that require finding and segmenting any object in any image, such as agricultural sectors, biological research, or even space exploration. Its ability to localize and track objects in videos could be beneficial for various scientific studies on Earth and beyond.

By sharing the research and dataset, the project aims to accelerate research into segmentation and more general image and video understanding. As a component in a larger system, SAM can perform segmentation tasks and contribute to more comprehensive multimodal understanding of the world, for example, understanding both the visual and text content of a webpage.

Looking ahead, tighter coupling between understanding images at the pixel level and higher-level semantic understanding of visual content could lead to even more powerful AI systems. The Segment Anything project is a significant step forward in this direction, opening up possibilities for new applications and advancements in computer vision and AI research.