Embeddings Visualization in FiftyOne

Overview

Visualize your dataset in 2D using deep learning embeddings and dimensionality reduction (UMAP/t-SNE). Explore clusters, find outliers, and color samples by any field.

Use this skill when:

• Visualizing dataset structure in 2D
• Finding natural clusters in images
• Identifying outliers or anomalies
• Exploring data distribution by class or metadata
• Understanding embedding space relationships

Prerequisites

• FiftyOne MCP server installed and running
• @voxel51/brain plugin installed and enabled
• Dataset with image samples loaded in FiftyOne

Key Directives

ALWAYS follow these rules:

1. Set context first

set_context(dataset_name="my-dataset")

2. Launch FiftyOne App

Brain operators are delegated and require the app:

launch_app()

Wait 5-10 seconds for initialization.

3. Discover operators dynamically

# List all brain operators
list_operators(builtin_only=False)

# Get schema for specific operator
get_operator_schema(operator_uri="@voxel51/brain/compute_visualization")

4. Compute embeddings before visualization

Embeddings are required for dimensionality reduction:

execute_operator(
    operator_uri="@voxel51/brain/compute_similarity",
    params={
        "brain_key": "img_sim",
        "model": "clip-vit-base32-torch",
        "embeddings": "clip_embeddings",
        "backend": "sklearn",
        "metric": "cosine"
    }
)

5. Close app when done

close_app()

Complete Workflow

Step 1: Setup

# Set context
set_context(dataset_name="my-dataset")

# Launch app (required for brain operators)
launch_app()

Step 2: Verify Brain Plugin

# Check if brain plugin is available
list_plugins(enabled=True)

# If not installed:
download_plugin(
    url_or_repo="voxel51/fiftyone-plugins",
    plugin_names=["@voxel51/brain"]
)
enable_plugin(plugin_name="@voxel51/brain")

Step 3: Discover Brain Operators

# List all available operators
list_operators(builtin_only=False)

# Get schema for compute_visualization
get_operator_schema(operator_uri="@voxel51/brain/compute_visualization")

Step 4: Check for Existing Embeddings or Compute New Ones

First, check if the dataset already has embeddings by looking at the operator schema:

get_operator_schema(operator_uri="@voxel51/brain/compute_visualization")
# Look for existing embeddings fields in the "embeddings" choices
# (e.g., "clip_embeddings", "dinov2_embeddings")

If embeddings exist: Skip to Step 5 and use the existing embeddings field.

If no embeddings exist: Compute them:

execute_operator(
    operator_uri="@voxel51/brain/compute_similarity",
    params={
        "brain_key": "img_viz",
        "model": "clip-vit-base32-torch",
        "embeddings": "clip_embeddings",  # Field name to store embeddings
        "backend": "sklearn",
        "metric": "cosine"
    }
)

Required parameters for compute_similarity:

• brain_key - Unique identifier for this brain run
• model - Model from FiftyOne Model Zoo to generate embeddings
• embeddings - Field name where embeddings will be stored
• backend - Similarity backend (use "sklearn")
• metric - Distance metric (use "cosine" or "euclidean")

Recommended embedding models:

• clip-vit-base32-torch - Best for general visual + semantic similarity
• dinov2-vits14-torch - Best for visual similarity only
• resnet50-imagenet-torch - Classic CNN features
• mobilenet-v2-imagenet-torch - Fast, lightweight option

Step 5: Compute 2D Visualization

Use existing embeddings field OR the brain_key from Step 4:

# Option A: Use existing embeddings field (e.g., clip_embeddings)
execute_operator(
    operator_uri="@voxel51/brain/compute_visualization",
    params={
        "brain_key": "img_viz",
        "embeddings": "clip_embeddings",  # Use existing field
        "method": "umap",
        "num_dims": 2
    }
)

# Option B: Use brain_key from compute_similarity
execute_operator(
    operator_uri="@voxel51/brain/compute_visualization",
    params={
        "brain_key": "img_viz",  # Same key used in compute_similarity
        "method": "umap",
        "num_dims": 2
    }
)

Dimensionality reduction methods:

• umap - (Recommended) Preserves local and global structure, faster. Requires umap-learn package.
• tsne - Better local structure, slower on large datasets. No extra dependencies.
• pca - Linear reduction, fastest but less informative

Step 6: Direct User to Embeddings Panel

After computing visualization, direct the user to open the FiftyOne App at http://localhost:5151/ and:

1. Click the Embeddings panel icon (scatter plot icon, looks like a grid of dots) in the top toolbar
2. Select the brain key (e.g., img_viz) from the dropdown
3. Points represent samples in 2D embedding space
4. Use the "Color by" dropdown to color points by a field (e.g., ground_truth, predictions)
5. Click points to select samples, use lasso tool to select groups

IMPORTANT: Do NOT use set_view(exists=["brain_key"]) - this filters samples and is not needed for visualization. The Embeddings panel automatically shows all samples with computed coordinates.

Step 7: Explore and Filter (Optional)

To filter samples while viewing in the Embeddings panel:

# Filter to specific class
set_view(filters={"ground_truth.label": "dog"})

# Filter by tag
set_view(tags=["validated"])

# Clear filter to show all
clear_view()

These filters will update the Embeddings panel to show only matching samples.

Step 8: Find Outliers

Outliers appear as isolated points far from clusters:

# Compute uniqueness scores (higher = more unique/outlier)
execute_operator(
    operator_uri="@voxel51/brain/compute_uniqueness",
    params={
        "brain_key": "img_viz"
    }
)

# View most unique samples (potential outliers)
set_view(sort_by="uniqueness", reverse=True, limit=50)

Step 9: Find Clusters

Use the App's Embeddings panel to visually identify clusters, then:

Option A: Lasso selection in App

1. Use lasso tool to select a cluster
2. Selected samples are highlighted
3. Tag or export selected samples

Option B: Use similarity to find cluster members

# Sort by similarity to a representative sample
execute_operator(
    operator_uri="@voxel51/brain/sort_by_similarity",
    params={
        "brain_key": "img_viz",
        "query_id": "sample_id_from_cluster",
        "k": 100
    }
)

Step 10: Clean Up

close_app()

Available Tools

Session View Tools

Brain Operators for Visualization

Use list_operators() to discover and get_operator_schema() to see parameters:

Common Use Cases

Use Case 1: Basic Dataset Exploration

Visualize dataset structure and explore clusters:

set_context(dataset_name="my-dataset")
launch_app()

# Check for existing embeddings in schema
get_operator_schema(operator_uri="@voxel51/brain/compute_visualization")

# If embeddings exist (e.g., clip_embeddings), use them directly:
execute_operator(
    operator_uri="@voxel51/brain/compute_visualization",
    params={