Dynaface computes the measurements below from facial landmarks that it places automatically: 98 points on a frontal view (the WFLW landmark scheme, detected by the SPIGA neural network) and six anatomical points along the traced outline of a profile view. The desktop and mobile apps and the Python and .NET libraries all use the same definitions. Each measurement can be turned on or off, drawn on the image, and exported to CSV under the column names listed with it.
How Values Are Reported
- Standard framing. Each photo, and each frame of a video, is scaled and cropped to a standard 1024 × 1024 image centered on the eyes before anything is measured.
- Millimeters. Distances (mm) and areas (mm²) are converted from pixels using the distance between the pupils. Dynaface assumes the population-average pupillary distance of 63 mm unless you enter the subject's measured value in Settings, so enter it when absolute sizes matter. Ratios and angles do not depend on this setting.
- Left and right are the subject's own sides. In a normal, unmirrored photo the subject's right side appears on the left of the image; a mirrored selfie swaps them.
- Symmetry ratios divide the smaller side by the larger, so 1.0 means the two sides are equal and lower values mean more asymmetry.
Frontal Symmetry Measures
Facial Asymmetry Index (FAI)
The distance from the inner corner of each eye (medial canthus) to the corner of the mouth (oral commissure) on the same side, compared between the two sides. FAI is the absolute difference between the left and right distances, in millimeters, so 0 means the two sides match. For the index's validation in smile restoration research, see Malm et al., Facial Asymmetry Index: Validation and Applications in Various Smile Restoration Techniques, Facial Plastic Surgery, 2018.
CSV: fai
Oral Commissure Excursion (Oral CE)
The distance from each corner of the mouth to the midpoint of the lower lip, in millimeters, reported separately for the left and right sides. Comparing values at rest and during a smile shows how far each corner moves.
CSV: oce.l, oce.r
Brow Height (Brow)
The difference in height between the left and right eyebrows, in millimeters, measured at the middle of each brow.
CSV: brow.d
Eye Area
The area of each eye opening (palpebral fissure), outlined by eight landmarks around the eyelid margins, in mm². Dynaface reports each side, the difference between them, and their symmetry ratio.
CSV: eye.left, eye.right, eye.diff,
eye.ratio
Dental Display
The area of the mouth opening inside the inner edges of the lips, where the teeth show during a smile, in mm². The opening is split at the facial midline, defined from the pupils, and Dynaface reports the total, each side, the difference between the sides, and their symmetry ratio.
CSV: dental_area, dental_left,
dental_right, dental_diff, dental_ratio
Frontal Distances
Intercanthal Distance
The distance between the inner corners of the eyes, in millimeters.
CSV: id
Outer Eye Corners
The distance between the outer corners of the eyes (lateral canthi), in millimeters.
CSV: oe
Mouth Length
The distance between the corners of the mouth, measured where the lips meet, in millimeters.
CSV: ml
Nose (Frontal)
Four horizontal widths of the nose seen from the front, in millimeters: across the nostrils, at the nasal tip, and at two heights along the nasal dorsum (its base and its bridge).
CSV: nostril, nose.tip, dorsal.base,
dorsal.bridge
Head Position, Pose, and Color
Position
The head's tilt in the image (the angle of the line between the pupils, in degrees), the pupil distance in pixels, and the resulting millimeters-per-pixel scale used for every millimeter measurement.
CSV: tilt, pd, px2mm
Pose
Estimated head rotation in degrees: pitch (nodding up and down), yaw (turning left and right), and roll (tilting toward a shoulder). Useful for checking that a subject was facing the camera.
CSV: pitch, yaw, roll
Skin Tone
The average color of two patches on the cheeks, as hue (degrees), saturation, and brightness (percent). Available for photos; it is not charted for video.
CSV: hue, sat, brightness
Profile (Lateral) Measures
When a photo shows the face from the side, Dynaface removes the background, traces the outline of the face from forehead to chin, and marks six points along it: soft tissue glabella, soft tissue nasion, nasal tip, subnasal point, mentolabial point, and soft tissue pogonion. These measurements are taken relative to the image's horizontal and vertical axes, so keep the head level in profile photos.
Nasofrontal Angle (NFA)
The angle at the soft tissue nasion between the soft tissue glabella and the nasal tip, in degrees.
CSV: nfa
Nasolabial Angle (NLA)
The angle at the subnasal point between the nasal tip and the soft tissue pogonion, in degrees.
CSV: nla
Nasal Tip Projection (AT/NT)
AT is the horizontal distance from the nasal tip back to a vertical line through the soft tissue nasion, and NT is the vertical distance from the nasion down to the level of the tip. Their ratio, AT/NT, describes how far the tip projects relative to the length of the nose. AT and NT are in pixels of the standard image; the ratio has no units.
CSV: at, nt, at_nt
For a profile photo, the CSV export contains the traced outline itself, one row per point, with the six anatomical points labeled.
Measuring Video
In a video, every frontal measurement above except skin tone is computed for each frame and plotted on a chart over the length of the clip. The CSV export has one row per frame with a time column. Two shortcuts jump to the frame with the greatest dental display or the widest eye opening, and the Evaluation report compares the eye measurements at maximum dental display with the dental measurements at maximum eye opening, the kind of comparison used in studies of oral-ocular synkinesis. See Research for published work that uses these measurements.