Moving from Wiimote to camera?

Question

I've been doing some Johnny Chung Lee-style Wiimote programming, and am running into problems with the Wiimote's relatively narrow field-of-view and limit of four points. I've bought a Creative Live! camera with an 85-degree field of view and a high resolution.

My prototype application is written in C#, and I'd like to stay there.

So, my question: I'd like to find a C#.Net camera / vision library that lets me track points - probably LEDs - in the camera's field of view. In the future, I'd like to move to R/G/B point tracking so as to allow more points to be tracked and distinguished more easily. Any suggestions?

Answer 1

Check out AForge.Net.. It seems to be a powerful library.

Answer 2

You could check out the Emgu.CV library which is a .NET (C#) wrapper for OpenCV. OpenCV is considered by many, including myself, to be the best (free) computer vision library.

Answer 3

With a normal camera, the task of identifying and tracking leds is quite more challanging, because of all the other objects which are visibile. I suggest that you try to maximize the contrast by reducing the exposure (thus turning of auto-exposure), if that's possible in the driver: you should aim for a value where your leds have still an high intensity in the image (>200) while not being overexposed (<255). You should then be able to threshold your image correctly and get higher quality results.

If the image is still too cluttered to be analyzed easily and efficiently, you may use infrared leds, remove the IR-block filter on the camera (if your camera has it), and maybe add an "Infrared Pass / Visible Light blocking" filter: you should then have bright spots only where the leds are, but you will not bee able to use color. There may be issues with the image quality though.

Answer 4

When tracking things like lights, especially if they are a special color, I recommend you apply a blur filter to the footage first. This blends out colors nicely, a while less accurate, will use less CPU and there's less threshold adjustments you have to do.