Veil-tiny

Veil-tiny

Veil-tiny is a 321,305-parameter visual privacy model built by Parergon.

It detects potentially sensitive regions directly from screenshots so they can be redacted locally, before the original image leaves the device.

No giant VLM. No cloud OCR round-trip. No sending the raw screenshot somewhere else just to decide what should have been hidden.

Screenshot
    ↓
Veil-tiny
    ↓
Sensitive-region mask
    ↓
Local redaction
    ↓
Sanitized screenshot

One tiny model. One job: decide what pixels should not leave your computer.

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Why Veil?

Real computer-use data is messy.

Screens can contain:

• emails
• names
• addresses
• account information
• credentials
• API keys
• customer information
• passwords
• private application state
• personal data

Large multimodal models can reason about screenshots.

But continuously running a giant model inside a lightweight desktop recorder is expensive, slow, and unnecessary.

Veil-tiny takes the opposite approach:

Make the privacy model extremely small and extremely specialized.

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Model

Veil-tiny does not need to decide whether something is specifically an email, phone number, API key, or account ID.

It answers a narrower question:

Should these pixels be redacted?

That narrow objective is what allows the model to stay tiny.

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Architecture

Veil-tiny uses a compact visual segmentation network with:

• depthwise-separable convolutional blocks
• lightweight encoder
• top-down decoder
• dense per-pixel prediction
• teacher-student knowledge distillation

The deployed student contains only 321K parameters.

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Training

Veil-tiny was trained from sensitive-region masks using WebPII and additional Parergon-generated desktop data.

WebPII

• 40,384 training screenshots
• synthetic web interfaces
• pixel-aligned sensitive-region annotations

Synthetic desktop data

An additional 10,000 generated desktop-style screenshots containing examples such as:

• authentication screens
• email-style interfaces
• terminals
• credentials
• API keys
• CRM-style interfaces
• account information
• dense desktop UI
• safe text and hard negatives

Knowledge distillation

A 1.22M-parameter teacher supervises the 321K-parameter student alongside ground-truth masks.

Ground-truth masks ─────────────┐
                                ↓
Screenshot → Teacher → Veil-tiny
              1.22M       321K

The goal is simple:

Transfer useful visual behavior into a model small enough to run locally.

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Held-out results

Evaluated on the held-out WebPII test set.

At a privacy-biased threshold of 0.10:

Threshold sweep

For privacy, maximizing ordinary F1 is not necessarily the best operating point.

Lower thresholds deliberately trade some precision for higher sensitive-region coverage.

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What does "leak-free" mean?

We use a deliberately unforgiving metric.

A screenshot only counts as leak-free when essentially all annotated sensitive regions are covered.

Missing a visible portion of even one sensitive region can fail the entire screenshot.

A privacy model should not get credit for blurring most of your API key.

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How Veil sees a screen

Veil produces a dense sensitivity probability map.

0.02 → probably safe
0.18 → suspicious
0.91 → likely sensitive

That map becomes a redaction mask.

Screenshot
    ↓
Veil-tiny
    ↓
Probability map
    ↓
Threshold
    ↓
Redaction mask

The operating point can be tuned depending on how aggressively the system should redact.

Lower threshold → more paranoid

Higher threshold → more selective

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An interesting failure mode

Veil-tiny can be too paranoid on complex desktop interfaces.

On unseen applications it may incorrectly redact ordinary information-dense regions such as:

• menu labels
• documentation
• filenames
• source code
• ordinary UI text

In other words, sometimes a tiny model learns:

lots of text = suspicious

instead of perfectly learning:

this particular information is private

We're publishing that limitation instead of pretending the problem is solved.

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Files

veil_tiny.pt

PyTorch checkpoint for research and experimentation.

veil_tiny.onnx

Portable ONNX model for lightweight local inference.

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Intended use

Veil-tiny is designed for research and experimentation around:

• privacy-preserving screen recording
• computer-use data
• GUI agents
• screenshot sanitization
• multimodal datasets
• local AI
• edge vision
• on-device privacy filtering

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Important

Veil-tiny is a research model, not a privacy guarantee.

It can miss sensitive content and should not currently be used as the sole privacy or security control protecting private information.

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Built small on purpose.

A visual privacy model for screen capture should be able to run where the screenshots are created.

321,305 parameters. Visual privacy before upload.

Built by Parergon.