Re: [CAD_CAM_EDM_DRO] Re: Camera software

On another off-topic project I'm working on, we're developing a stereo vision system to accurately make depth measurements by using controlled illumination and location techniques to average over an arbitrary number of frames. The application is a bit different here, but the same software should be able to build an triangle mesh model of a part that is rotated in its view. The more frames captured, the more accurate the model. The optics are soft-cal, so they only need to be digicam grade. We intend to do an experiment with laser to project a texture, but there's added cost there.

By accurate, it's hard to say without knowing how big it is, but a fist-sized part taking up the full frame should be able to measure about a thousandth of an inch after several hundred frames. Averaging would be a square root function. A hundred times the number of frames, (about an hour) should get 10x the accuracy. Depends on the quality of your CCD, it's resolution, thermal stability of all the parts, so this can go up or down an order of magnitude pretty easily.

It doesn't work as well with high polish metal, but then again, you never really encounter that kind of thing on the road... or something.

On 8/1/06, ballendo <ballendo@...> wrote:
Dennis,

Depends upon what you mean by "accurate" and "measurement";

Check out ScanZ and Dan Mauch's low cost 3d digitiser...

Are these along the lines<pun intended<G> of what you mean?

Ballendo

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Dennis Schmitz"
<denschmitz@...> wrote:
>
> If someone had software that would allow accurate measurement of parts
> by use of camera input only, and perhaps a light, would there be a
> market for it?
>
> If it's been done already, I'd be feeling two months' effort level
> gratitude if you'd kindly point me to it...