Fig. 3
From: Video pulse rate variability analysis in stationary and motion conditions
Video image processing: a original frame; b ROIf and ROIe; c feature points detected on frame; d ROI filter; e green channel of frame; f binary image; g multiplication resulting image from d–f. All pixels with non-zero values from g image were averaged across all the video sequence to obtain a raw iPPG signal. The subject gave permission to publish his photo in the paper