The application provides a non-contact
respiratory signal extraction method based on
infrared thermal imaging video data, comprising the following steps: step 1, using a
face detection and face key point positioning model on the original
infrared video frame, and combining a sparse
optical flow method to obtain the key point coordinates of each frame; step 2, obtaining a final
region of interest; step 3, mapping the final
region of interest back to the original
infrared video frame without enhancement to obtain an original
signal sequence; step 4, performing empirical mode
decomposition on the original
signal sequence to obtain an intrinsic mode function; according to the
respiratory frequency characteristics, selecting the intrinsic mode function obtained by
decomposition to reconstruct a reconstructed
signal, performing band-pass filtering on the reconstructed signal to obtain a final
respiratory signal; analyzing the power spectrum of the final
respiratory signal, identifying the peak frequency point with the
maximum amplitude, and calculating the final
respiratory rate. The application has
high motion robustness, and solves the common loss of lock problem in non-contact measurement through the
cascade of multiple tracking mechanisms.