raspberry pi + pi noir camera + ir led (940nm) = vein viewer

The title says most of it. Connect a Raspberry Pi NoIR camera and a near infrared LED and in less than three minutes you can get a basic vein contrast image.

I used a 3 W, 940 nm LED because I already had one from another project. Other near infrared LEDs between approximately 740 nm and 940 nm should also work, although the contrast and required exposure will change with wavelength.

For this test I placed the LED at about a 15 degree angle to the camera. The Pi NoIR camera does not have the normal infrared blocking filter, so it can see the reflected near infrared light.

The image can be improved in OpenCV with histogram equalization. Another idea was to add a small laser or LED projector and project the processed image back onto the hand.

OpenCV Raspberry Pi camera guide:

http://www.pyimagesearch.com/2015/03/30/accessing-the-raspberry-pi-camera-with-opencv-and-python/

Video:

https://www.youtube.com/watch?v=X_EvUTjfb94

Original parts and reference links

• aliexpress 850nm 3w leds
• CLICK HERE

Photos and videos