Explane blobconfig, bbox in config.xml? & feature request. 
Posted: 30 November 2007 04:59 PM   [ Ignore ]
Rank
Joined  2007-10-11
Total Posts:  20
New Member

I was wondering, if someone could explain to me exactly what blobconfig, and bbox do in the config.xml

<blobconfig distanceThreshold="250" minDimension="2" maxDimension="250" ghostFrames="0" minDisplacementThreshold="2.000000" />
<
bbox ulX="0.0" ulY="0.0" lrX="1.0" lrY="1.0" />

and could you also explain each of the parameters in blobconfig, My guess, is that minDimension, and maxDimension, have to do with the mext, and smallest side of blob it will detect, but what is distanceThreshold, ghostFrames, and minDisplacementThreshold?

and what exactly does bbox do? I understand what the values do, they make a box, but what exactly does it do? ignore camera capture outside the box? ignore that portion of the monitor outside the box? or what?

I’ve searched and found no information on this on the forums or wiki.

thanks in advanced.

_

I also have a suggestion/request for touchlib, even though bbox might do this to a point, I still don’t quite understand its functionality.

A vertex-shape mask, to add on as part of the filters for the config.xml. I’ll explain, this would be a shape, that you’d draw over your camera capture, in most cases 4 corners, in others maybe a few more, so that everything outside the shape is ignored, this would be extreamy helpful, in both DI, and FTIR , where the camera is at an extreme or awkward angle.

my reasoning behind this is because in some cases with FTIR, and most cases with DI, you get noise around the edges of the acrylic. being able to completely ignore the edges, would make it vary easy to calibrate, and use. instead of having to get perfect lighting conditions for edge noise. look at attached picture for example. everything outside the blue area would be ignored/always black.

comments welcome,
Will

Image Attachments
example_mask.jpg
Profile
 
 
Posted: 05 December 2007 11:16 AM   [ Ignore ]   [ # 1 ]
Rank
Joined  2007-10-11
Total Posts:  20
New Member

I guess no one else understands the extent of those 2 configuration strings? and i also guess no one cares for my suggestion....

anyone?

Profile
 
 
Posted: 05 December 2007 01:34 PM   [ Ignore ]   [ # 2 ]
Avatar
RankRankRankRankRankRank
Joined  2007-04-08
Total Posts:  2539
Dedicated

For some reason I missed your post before. The bbox is the calibration bounding box which sets the area that touchlib looks for blobs.  I don’t quite remember what the other values do. The reason these aren’t mentioned much is because these are things that you don’t have to edit within the config yourself since touchlib does that automatically within the configapp. For example when you open configapp, and hit ‘enter’ you get directions on how to move around the bounding box (hitting ‘x’wink as well as other directions.

There was a new filter recently added that lets you crop out (only in a square) the unused part of the image. So check out the new “crop” filter. I agree though that something more advanced would be better where you could draw the actual mask you want and aren’t limited to a square/rectangle.

 Signature 

MTmini, MTbiggie, & Audiotouch creator & Community Core Vision Co-founder

Follow on:
My Blog | Facebook | Twitter | Youtube

Profile
 
 
Posted: 18 December 2007 06:35 PM   [ Ignore ]   [ # 3 ]
RankRank
Joined  2006-11-09
Total Posts:  123
Member

Will, the background removal filter already does exactly that, but you don’t see it when you run the config app - only other apps. It uses the camera calibration points as the shape mask.

Profile
 
 
Posted: 19 December 2007 11:06 PM   [ Ignore ]   [ # 4 ]
Rank
Joined  2007-10-11
Total Posts:  20
New Member

Ahh, i guess i didn’t skim over the code well enough, thanks White. it doesn’t quite solve the issue with initial calibration, but at least I know now, it shouldn’t cause issues after its calibrated.

Profile
 
 
Posted: 20 December 2007 07:32 AM   [ Ignore ]   [ # 5 ]
RankRank
Joined  2006-11-09
Total Posts:  123
Member

One trick I used last time to calibrate - use an IR pen (or a TV remote, or a non-LED flashlight..) to calibrate instead of your fingers. You should be able to turn up your thresholds and you’ll be much less subject to noise..

Profile