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Frequently Asked Questions

A lot of these questions have been extracted from the ARToolKit Mailing List and all the persons contribute to reply and help newbies. We want personnaly thanks: Blair McIntyre, Daniel Wagner for their large participation.
General Questions
What is ARToolKit?
ARToolKit is a C and C++ language software library that lets programmers easily develop Augmented Reality applications.
Where can I find it?
In the download section.
Where can I find the last version of ARToolKit?
Simple instructions on how to configure a CVS client to get the latest ARToolKit source from CVS are at .
Who maintains ARToolKit?
ARToolKit is primarily being developed by Dr. Hirokazu Kato of Osaka University, Japan, and is being supported by the Human Interface Technology Laboratory (HITLab) at the University of Washington, and HIT Lab NZ at the University of Canterbury, New Zealand.
Which license policy applies to ARToolKit?
Where I can find more information on ARToolKit?
If you don't find answers to all your question on the website, You can contact for further informations.
Technical Questions
I see nothing my Image is only black ?
This can happen if the video driver doesn't work properly and no image is returned. Try to run your camera with other video viewer to check if the video driver are all rights. You can use amcap.exe on Windows, XXX on Linux or XXX on MacOS.
I see nothing my Image is blue?
This can happen with video TV card. Generally you have the bad channel input used with ARToolKit. You can change it manually on vconf or with the intermediate of GUI program (like amcap->Video Filter..).
My image is upside down !!
You need to add the 'flipV' parameter to vconf.
Which format my camera used ?
At present in the toolkit (v2.70.1) the video format used is determined at compile-time, by options in config.h. Take a look and see what format is being used.
I'm trying to compile example under Windows platform the compiler shows the error message : "streams.h" is not found ?
with last directX: You need to get the SDK Extras download and install it into the SDK directory 9.0 SDK Update (Feb 2005) Extras link
I have the fatal error C1083: Cannot open include file: 'GL/glext.h': No such file or directory ?
the missing glext.h arises because lots of people having OpenGL headers for OpenGL 1.2, and glext.h was not separated out of gl.h until 1.3. You can find it:
I get the error msg when I start the simpleTest program: "this device can not be supported by libARvideo. (vm.frames < 2)" ?
ARtoolkit test if your camera can do double buffering (vm.frames) : if not the camera is rejected it (the message error). try to reinstall the latest version of your driver.
On Windows, I have identifiers such as DWORD_PTR, LONG_PTR undefined ?
The kind of errors you are seeing are typical if you are trying to use DirectX 9.0c with Visual Studio 6, as DirectX 9.0c does not support Visual Studio 6.
How I get the distance between two Markers ?
The last column of the patt_trans matrix is the relative translation between marker and camera. For the second marker, the camera is the same, so you can use the inverse of the second patt_trans matrix to multiply the first one, then you will get the relative translation between these two markers. inv=inverse(Matrix1); Matrix3=inv*Matrix2; Matrix1 is the transformation of marker 1 Matrix2 is the transformation of marker 2 Matrix3 is the relation of marker 1 and 2. If you check the translation column of matrix 3, you can see the distance between marker 1 and 2. Check the example relation distribute with ARToolKit.
On Linux, I have this error:arVideoOpen: width or height oversize
The Video4Linux driver in ARToolKit is coded to request a particular sized video frame and if your camera does not support that resolution then it will fail with that error message. If you supply -width and -height arguments inside simpleTest (by vconf variable) then it will prevent this error message.
I am using a "something 1394" webcam which supports 30 frames per second at a resolution of 640x480. However the frame rate is always less than 15 fps.
One thing to do is make sure you have the drivers installed. If it saws "Generic 1394 Camera" or something like that in hardware manager, then you are using the default windows drivers, which can only do 15 fps with these sorts of cameras.