You can remove most of the jitter by using information from the previous
frame, for pattern detection AND transformation computation.
To make ATK use previous image information, use "arDetectMarker" instead of
This latter makes ATK to look into the whole image in every frame.
To compute the transformation matrix using the previously computed one (and
therefore changing the value only if the difference between the two is
important use "arGetTransMatCont" instead of "arGetTransMat". You have to
store the previous position of the object by doing something like this:
arGetTransMatCont(&marker_info[k], previous_trans, object[i].center,
previous_trans = object[i].trans;
You must remember that the result is more stable, although less acurate,
since the matrix is not recomputed in every frame!
All information above has been found by looking at header files, unofficial
documentation, informal documents etc. Therefore, the comments concerning
the code are just assumptions. I don't know if everything is correct, but
the result DOES look nicer.
Hope this helps,
De : owner-artoolkit@h ..................
[mailto:owner-artoolkit@h ..................]De la part de Rainer Blum
Envoyé : mardi 21 janvier 2003 10:42
À : artoolkit@h ..................
Objet : Stable tracking with ARToolkit
I'm looking for some help concerning the
stability of the tracking of ARToolKit.
If a human being holds the pattern in his hand
you have some kind of shivering effect since
ATK processes (of course) every smallest
I heard that there are some references
to source code solving this problem.
Can someone provide me with these references
or even with code solving this problem?
Any help is appreciated!
Dipl.-Inf. (FH) Rainer Blum
idmk - Institut für digitale Medien und Kommunikation
eMail: blum@i ......