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Earlier quoted context omitted.
It's precise enough for the application. Webcams typically have a 15-30 fps framerate. Heartrates are typically 30-200 bpm (~= 0.5 to 3.3 bps).
It seems that the Nyquist-Shannon sampling rate would be too low for the results to be accurate.
[1] https://play.google.com/store/apps/details?id=si.modula.andr...
Awesome. Could open up a whole field of applications.
There is already an Android app[1] that does something similar. You put your finger up to the rear-camera and it detects your heart rate. [1] https://play.google.com/store/apps/details?id=si.modula.andr...
See also: http://people.csail.mit.edu/mrub/vidmag/
Earlier quoted context omitted.
It seems that the Nyquist-Shannon sampling rate would be too low for the results to be accurate.
No ? The frequency needs to be at-least double this seems the be the case. However webcam noise and the algorithm might increase the need.
Earlier quoted context omitted.
No ? The frequency needs to be at-least double this seems the be the case. However webcam noise and the algorithm might increase the need.
The webcam framerate should be at least double the heart rate to get an accurate measurement, not the other way around.
15 fps (worst case framerate) vs 3 bps (worst case heart rate)
Earlier quoted context omitted.
The webcam framerate should be at least double the heart rate to get an accurate measurement, not the other way around.
And isn't this the case? 15 fps (worst case framerate) vs 3 bps (worst case heart rate)
This is what I suspect could happen, with two possible heart rates matching the same set of samples:
http://upload.wikimedia.org/wikipedia/commons/2/28/AliasingS...
