Eye blinks are measured by first calculating a variable called eye aspect ratio (EAR), which we get from here, and is basically just a quantification of how open the eye is. Over the course of a video, the EAR ends up being a vector whose troughs most likely signify individual eye blinks. The troughs are identified using a find peaks function and for each trough, the EAR value is outputted along with the other raw variables described below.
Raw Variables
Variable
Description
mov_blink_ear
Eye aspect ratio i.e. a vector derived from this model at points in the video where an eye blink was detected.
mov_blinkframe
Eye blink times are indices of the video frames where an eye blink was detected.
mov_blinkdur
Durations between blinks is the time spanned between the current blink and the previous blink in seconds.
Derived Variables
Variable
Description
mov_blink_ear_mean
Eye aspect ratio mean i.e. the mean of the vector mov_blink_ear.
mov_blink_ear_std
Eye aspect ratio standard deviation i.e. the standard deviation of the vector mov_blink_ear.
mov_blink_count
Number of blinks measured over the course of the video.
mov_blinkdur_mean
Mean duration between eye blinks measured in seconds.
mov_blinkdur_std
Standard deviation of duration between eye blinks measured in seconds.
