Table 3.

Averaged areas under the curve (AUCs) obtained by training conditional random fields on the feature sets

AU	Name	NSV	SNTV	SIFT	Combined
1	Inner Brow Raiser	0.8947 ± 0.0232	0.8834 ± 0.0243	0.8170 ± 0.0292	0.8545 ± 0.0267
2	Outer Brow Raiser	0.9278 ± 0.0239	0.9270 ± 0.0240	0.8642 ± 0.0317	0.8630 ± 0.0318
4	Brow Lowerer	0.8277 ± 0.0271	0.8667 ± 0.0244	0.8078 ± 0.0283	0.8581 ± 0.0251
5	Upper Lip Raiser	0.8857 ± 0.0315	0.9070 ± 0.0288	0.8723 ± 0.0330	0.8326 ± 0.0370
6	Cheek Raiser	0.8740 ± 0.0299	0.8691 ± 0.0304	0.8756 ± 0.0298	0.8685 ± 0.0305
7	Lip Tightener	0.8484 ± 0.0326	0.8633 ± 0.0312	0.8277 ± 0.0343	0.8131 ± 0.0354
9	Nose Wrinkler	0.9415 ± 0.0271	0.9401 ± 0.0274	0.8960 ± 0.0352	0.8782 ± 0.0378
11	Nasolabial Deep.	0.8818 ± 0.0554	0.9270 ± 0.0446	0.8766 ± 0.0564	0.8799 ± 0.0558
12	Lip Corner Puller	0.9171 ± 0.0241	0.9222 ± 0.0234	0.8813 ± 0.0283	0.9066 ± 0.0254
15	Lip Corner Depr.	0.9178 ± 0.0282	0.9239 ± 0.0272	0.8939 ± 0.0316	0.8700 ± 0.0345
17	Lower Lip Depr.	0.9017 ± 0.0209	0.9125 ± 0.0198	0.8397 ± 0.0257	0.8669 ± 0.0238
20	Lip Stretcher	0.8713 ± 0.0377	0.8918 ± 0.0349	0.7810 ± 0.0465	0.8430 ± 0.0409
23	Lip Tightener	0.9399 ± 0.0307	0.9412 ± 0.0304	0.9128 ± 0.0364	0.8864 ± 0.0410
24	Lip Pressor	0.9275 ± 0.0341	0.9408 ± 0.0310	0.9179 ± 0.0361	0.8895 ± 0.0412
25	Lips Part	0.9075 ± 0.0177	0.8961 ± 0.0186	0.8816 ± 0.0197	0.9132 ± 0.0172
26	Jaw Drop	0.8847 ± 0.0452	0.8876 ± 0.0447	0.8771 ± 0.0464	0.8176 ± 0.0546
27	Mouth Stretch	0.9455 ± 0.0252	0.9459 ± 0.0251	0.9073 ± 0.0322	0.8958 ± 0.0340
ALL	Averaged	0.8997 ± 0.0303	0.9086 ± 0.0288	0.8665 ± 0.0342	0.8669 ± 0.0349

All AUCs are computed using leave-one-subject-out cross-validation. An upper bound on the uncertainty of the AUCs is also presented. Best performance for each action unit is boldfaced. See text for details