2.2 KiB
2.2 KiB
id, title
| id | title |
|---|---|
| action-units | Action units |
Action units (AUs) are individual facial musculature arrangements specified in the Facial Action Coding System (FACS), combinations of which can account for all possible facial expressions1 . OpenDBM outputs framewise values for AU presence and intensity for the following AUs:
| Action unit number | Description |
|---|---|
| AU1 | Inner brow raiser |
| AU2 | Outer brow raiser |
| AU4 | Brow lowerer |
| AU5 | Upper lid raiser |
| AU6 | Cheek raiser |
| AU7 | Lid tightener |
| AU9 | Nose wrinkler |
| AU12 | Lip corner puller |
| AU15 | Lip corner depressor |
| AU16 | Lower lip depressor |
| AU20 | Lip stretcher |
| AU23 | Lip tightener |
| AU26 | Jaw drop |
For each of the AUs in the table above, the following raw variables are calculated:
Raw Variables
| Variable | Description |
|---|---|
fac_auXXpres |
Action Unit presence, where XX refers to the action unit. This is a binary (1/0) variable, where 1 signifies presence of the action unit and 0 signifies its absence as determined by OpenFace. |
fac_auXXint |
Action Unit intensity, where XX refers to the action unit. This is a continuous (0-5) variable, where 0 signifies no presence and 5 signifies maximum presence, as determined by OpenFace. |
Derived Variables
| Variable | Description |
|---|---|
fac_auXXpres_pct |
Action Unit presence percentage. Using the binary vector fac_auXXpres, the percentage of video frames where an AU was present is calculated into this variable. |
fac_auXXint_mean |
Action Unit intensity mean. Mean value of fac_auXXint over the course of the video. |
fac_auXXint_std |
Action Unit intensity standard deviation. Standard deviation of fac_auXXint over the course of the video. |
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Ekman, R. (1997). What the face reveals: Basic and applied studies of spontaneous expression using the Facial Action Coding System (FACS). Oxford University Press, USA. ↩︎