  In recent years, research about monitoring vital signs by smartphones grows
significantly. There are some special sensors like Electrocardiogram (ECG) and
Photoplethysmographic (PPG) to detect heart rate (HR) and respiration rate
(RR). Smartphone cameras also can measure HR by detecting and processing
imaging Photoplethysmographic (iPPG) signals from the video of a user's face.
Indeed, the variation in the intensity of the green channel can be measured by
the iPPG signals of the video. This study aimed to provide a method to extract
heart rate and respiration rate using the video of individuals' faces. The
proposed method is based on measuring fluctuations in the Hue, and can
therefore extract both HR and RR from the video of a user's face. The proposed
method is evaluated by performing on 25 healthy individuals. For each subject,
20 seconds video of his/her face is recorded. Results show that the proposed
approach of measuring iPPG using Hue gives more accurate rates than the Green
channel.
