Algorithm: HR Estimation.

Input: Frames from previous section 1. Detrend the signal 2. Perform bandpass filtering to contain signal in the [0.7-4] Hz band 3. Perform Fast Fourier Transform [FFT] on the 30 second sliding window from the previous step and calculate the Power Spectral Density [PSD] and normalize it 4. Find corresponding frequency of the highest/peak power value of the power spectrum 5. Multiply the frequency value by 60 and display the B.P.M.

Output: Heart rate of the subject in beats per minute [B.P.M.]