Table 1.
The current micro-expression databases.
Table 2.
Video episodes used for eliciting micro-expressions and participants' rating scores.
Figure 1.
Acquisition setup for elicitation and recording of micro-expressions.
Table 3.
Criteria for labeling the emotions and the frequency in the database*.
Figure 2.
A demonstration of the frame sequence in a micro-expression.
The apex frame presents at about 110-expression is 4+9 (with AU 17 kept almost unchanged), which indicates disgust. The three rectangles above the images show the right inner brow (AU 4) in “zoom in” mode. The movement is more obvious in video play than picture sequence.
Figure 3.
Block diagram of the micro-expression classification.
Figure 4.
The LBP operator and its histogram.
Figure 5.
The texture of three planes and the corresponding histograms. (a) XY, XT and YT planes of a micro-expression sample, (b) concatenated LBP-TOP feature.
Table 4.
Performance on recognizing 5-class micro-expressions with LBP-TOP features extraction and leave-one-out cross-validation.