Facial Symmetry Analysis: new feature in the HF Space demo

[dreamlessx]

We just shipped a facial symmetry analysis feature to the LandmarkDiff HF Space demo.

What it does

Upload a face photo and the new Symmetry Analysis tab will:

1. Detect the facial midline from forehead to chin using MediaPipe mesh landmarks
2. Reflect left-side landmarks across the midline and measure Euclidean distance to their right-side counterparts
3. Normalize distances by the inter-pupil distance for scale-invariance
4. Report per-region scores (eyes, brows, cheeks, mouth, jaw) on a 0 to 100 scale
5. Render a color-coded overlay: green (>80), yellow (50 to 80), red (<50)

There is also a comparison mode where you can upload pre- and post-procedure photos to see how symmetry changed.

Technical details

• Uses 22 bilateral landmark pairs across 5 facial regions (defined in SYMMETRY_PAIRS)
• Midline computed from landmarks 10 (forehead top) and 152 (chin bottom)
• Score uses exponential decay: 100 * exp(-3 * normalized_distance) so small asymmetries are penalized gently
• Robust image preprocessing handles RGBA, grayscale, float images, and auto-adjusts brightness via CLAHE
• Detailed face detection error hints for common failure modes (too dark, low contrast, unusual aspect ratio)

Try it

Head to the live demo and switch to the Symmetry Analysis tab.

Feedback welcome, especially on the scoring calibration and which regions matter most to you.