The invention discloses an
optical flow gradient amplitude characteristic-based subtle
facial expression detection method and relates to
processing for identifying a graphic recording carrier. According to the method, face edges are obtained by means of fitting according to face key points, and a face
region of interest is extracted; an
optical flow field between face image frames in a
video sequence is extracted by using a FlowNet2 network; the
optical flow gradient amplitude characteristics of the face
region of interest are extracted; characteristic distances are calculated and processed, and
noise elimination is carried out; and therefore, subtle
facial expression detection based on the optical flow gradient amplitude characteristics is completed. According to subtle facial expressiondetection in the prior art, subtle
facial expression motion cannot be captured in extracted face
image motion features; the features contain excessive interference information, and as a result, the subtle facial expression detection is susceptible to the influence of head deviation, blinking motion, accumulated
noise and single-frame
noise in feature
distance analysis. However, with the method adopted, the above defects in the prior art can be eliminated.