1     Definition 2     Functional Requirements 3     Syntax
4     Semantics 5    Conformance Testing 6     Performance Assessment

1    Definition

Face Descriptors is a Data Type representing the features of the Face of an Entity.

2     Functional Requirements

The Face Descriptors represent the effect of the motion of the muscles of a human face.

The Face Descriptors Syntax represents the Actions Units of the Facial Action Coding System (FACS) originally developed by Carl-Herman Hjortsjö, adopted by Paul Ekman and Wallace V. Friesen (1978) and updated by Ekman, Friesen, and Joseph C. Hager (2002).

3     Syntax

https://schemas.mpai.community/PAF/V1.3/data/FaceDescriptors.json

4     Semantics

Header N1 Bytes Orientation FaceDescriptors
– Standard-FaceDescriptors 9 Bytes The characters “OSD-FCD-V”
– Version N2 Bytes Major version – 1 or 2 characters
– Dot-separator 1 Byte The character “.”
– Subversion N3 Bytes Minor version – 1 or 2 characters
FaceDescriptorsID N4 Bytes Identifier of Face Descriptors.
AU Description N5 Bytes Facial muscle generating the Action
1 Inner Brow Raiser 1 Byte Frontalis, pars medialis
2 Outer Brow Raiser 1 Byte Frontalis, pars lateralis
4 Brow Lowerer 1 Byte Corrugator supercilii, Depressor supercilii
5 Upper Lid Raiser 1 Byte Levator palpebrae superioris
6 Cheek Raiser 1 Byte Orbicularis oculi, pars orbitalis
7 Lid Tightener 1 Byte Orbicularis oculi, pars palpebralis
9 Nose Wrinkler 1 Byte Levator labii superioris alaquae nasi
10 Upper Lip Raiser 1 Byte Levator labii superioris
11 Nasolabial Deepener 1 Byte Zygomaticus minor
12 Lip Corner Puller 1 Byte Zygomaticus major
13 Cheek Puffer 1 Byte Levator anguli oris (a.k.a. Caninus)
14 Dimpler 1 Byte Buccinator
15 Lip Corner Depressor 1 Byte Depressor anguli oris (a.k.a. Triangularis)
16 Lower Lip Depressor 1 Byte Depressor labii inferioris
17 Chin Raiser 1 Byte Mentalis
18 Lip Puckerer 1 Byte Incisivii labii superioris and Incisivii labii inferioris
20 Lip stretcher 1 Byte Risorius with platysma
22 Lip Funneler 1 Byte Orbicularis oris
23 Lip Tightener 1 Byte Orbicularis oris
24 Lip Pressor 1 Byte Orbicularis oris
25 Lips part 1 Byte Depressor labii inferioris or relaxation of Mentalis, or Orbicularis oris
26 Jaw Drop 1 Byte Masseter, relaxed Temporalis and internal Pterygoid
27 Mouth Stretch 1 Byte Pterygoids, Digastric
28 Lip Suck 1 Byte Orbicularis oris
41 Lid droop 1 Byte Relaxation of Levator palpebrae superioris
42 Slit 1 Byte Orbicularis oculi
43 Eyes Closed 1 Byte Relaxation of Levator palpebrae superioris; Orbicularis oculi, pars palpebralis
44 Squint 1 Byte Orbicularis oculi, pars palpebralis
45 Blink 1 Byte Relaxation of Levator palpebrae superioris; Orbicularis oculi, pars palpebralis
46 Wink 1 Byte Relaxation of Levator palpebrae superioris; Orbicularis oculi, pars palpebralis
61 Eyes turn left 1 Byte Lateral rectus, medial rectus
62 Eyes turn right 1 Byte Lateral rectus, medial rectus
63 Eyes up 1 Byte Superior rectus, Inferior oblique
64 Eyes down 1 Byte Inferior rectus, Superior oblique

5     Conformance Testing

A Data instance Conforms with Face Descriptors (PAF-FCD) V1.3 if t

  1. The Data validates against the Face Descriptors’ JSON Schema.
  2. All Data in the  Face Descriptors’ JSON Schema
    1. Have the specified type.
    2. Validate against their JSON Schemas.

6     Performance Assessment