benbritten.com

So, a bit more about the software the i am writing to run the multi-touch table that I am building (have kinda built a prototype of).

I just spent a few days getting the 'SG Settings' to work properly. I have been writing Cocoa for too long now and I am woefully unfamiliar with the Carbon stuff (ie all the old quicktime calls). I thought about using QTCapture, but it doesnt support IIDC settings like changeing the exposure from the code, so I am stuck (for now) with the Sequence Grabber Carbon stuff. Which just means wading through tons of sample code and docs to figure out what i need. In any case, now I can set the various exposure/gain/etc for the camera and have it save and come back when i load the program next.

This is immensely good.

The biggest problem i was having previous to this minor breakthrough was just that the camera driver (or camera itself maybe) does the auto-exposure/auto-brightness thing. So, the more fingers you put down, the more the xposure/brightness would change (albeit slightly, but slightly enough to mess up my thresholding stuff). Doesn't matter now, all fixed.

The next step is getting my configuration 'system' all worked out and the interface made as well as getting a nice generic coordinate-conversion thing working nice (right now it is pretty rough and inelegant) so that the underside of the surface that the camera looks at maps properly to the top of the surface that the computer is generating. Right now it is mostly just hard-coded for this specific setup. I need to make it configurable. This week hopefully.

Also, i successfully ran it on my old G, and it performed the same as the macbookpro, so that is good. I still havent done any optimizing yet, so I am fairly happy that the performance is good even in this very early stage. (my first few attempts at region-growing blob detection algos were horribly processor intensive)