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Accuracy
« on: October 07, 2008, 01:20:17 PM »
Hi !
I'm creating a table of comparison between low cost 3D laser scanner techniques. In this table I have put some parameters: cost,accuracy, possibility to scan undercuts. Please, could anyone say me the accuracy of Video WebCam Point Cloud Scanner?
I have seen a very good scan " Arts_Prop.JPG " ....compliments!
If you want, I will post my table of comparison...but, I have never used your technique (also because I haven't a CNC machine) ...I'm using David Laser Scanner!! (a low cost technique like yours!)  :)
Thank you, Andrea. 
Re: Accuracy
« Reply #1 on: October 08, 2008, 02:17:08 AM »
Hello Andrea,

>> Please, could anyone say me the accuracy of Video WebCam Point Cloud Scanner?

Using inexpensive CCD cameras with 640 x 480 pixels you can expect accuracy of about 1% of the field of view. The field of view depends on the camera lens and the size of the CCD array. A higher resolution CCD array might produce more accuracy with the same optics but not necessarily. You would also need to optimize the laser spot size and use high quality optics.

High accuracy is usually achieved by using a longer focal length camera lens to view a smaller field. The laser spot is also as small as possible according to diffraction limits. To scan a large object with a video probe that has a small field of view, you need to collect and process many stripes of data over the 3d volume of interest.

Tom Hubin
thubin@earthlink.net