yarPPG
yarPPG is yet another implementation of remote
PhotoPlethysmoGraphy.
Remote photoplethysmography (rPPG) refers to the camera-based measurement
of a blood volume pulse signal. It works by detecting small changes in skin
color, originating from the pulsation of blood[^1].
[!CAUTION]
This is just a hobby project. Intended for demo purposes only, the
provided program/code is not suitable to be used in a clinical setup
or for any decision making in general.
[!IMPORTANT]
October 2024 Update - yarPPG has seen a major overhaul. The rPPG
processing logic has been completely decoupled from the user interface
which now also allows offline processing. Not all features have yet
been ported to the new code base.
Please submit an issue if you miss something from the old version!
Documentation
The documentation pages are here: https://samproell.github.io/yarppg/
Installation and usage
In order to run the yarPPG application, clone this repository and navigate
to the downloaded folder. You can then install the folder into your Python
environment. This will install the run-yarppg command.
git clone https://github.com/SamProell/yarppg.git
cd yarppg
pip install "."
run-yarppg
Core functionality
Different from earlier versions of yarPPG, the core functionality for remote PPG
signal extraction has been completely decoupled from the user interface.
The Rppg class combines all required steps (roi identification, signal extraction,
heart rate estimation) into one (stateful) function.
import yarppg
rppg = yarppg.Rppg()
while running:
# frame = ... # get an image array of shape h x w x 3
result = rppg.process_frame(frame)
print(f"Current rPPG signal value: {result.value} (HR: {result.hr})")
See this guide if you need more
fine-grained control over the individual calculation steps.
The Rppg class also comes with a method to process an entire video file
at once. See more details here.
User interfaces
The default user interface launched by the run-yarppg command is a simplistic
window based on OpenCV.
More elaborate user interfaces are available, but require additional dependencies.
Simple Qt6 window
pip install ".[qt6]"
run-yarppg ui=qt6_simple
More to come, you are welcome to contribute
[^1]: W Verkruysse, L O Svaasand and J S Nelson. Remote plethysmographic
imaging using ambient light. Optics Express. 2008;16(26):21434–21445.
doi:10.1364/oe.16.021434
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