Abstract：Camera-based image photoplethysmography method enables a low-cost, non-contact way to estimate physiological parameters. The method based on chrominance model has a high computational efficiency and motion resistance. However, this model ignores the interference caused by the illumination fluctuations. Considering this problem, this paper proposed an improved chrominance model. In this model, we defined the reflection model of the ROI area and background area and subtract the illumination interference by using the ratio of these two area. So we can get a new chrominance model without illumination interference and use it to extract the pulse signal and estimate the heart rate. By using the face images from 10 subjects, we found the average relative error of heart rate estimated by this method was only 3.52%±2.53% and the average relative error of heart rate estimated by previous chrominance method was 7.23%±2.82%, which has significant difference (P<0.01). It also improved the signal\|to\|noise of the extracted pulse signal by 1.52 dBcompared to the chrominance model. It has an important significance on the non\|contact estimation of heart rate and extraction of pulse signal.
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