using ARToolkit

the good old ARToolKit.. less performances, less features.. but known to work and to be cross-platform..

our goal is to build an external for pd embedding artoolkit and taking gem images as input and giving markers positions as output

1. compiled a dummy gem external with artoolkit code: ok
2. using gem images as input: maybe (nothing recognized)
3. loading markers: maybe (nothing recognized)
4. detecting markers: maybe (nothing recognized yet)
5. detecting multiple markers: maybe (nothing recognized yet)
6. decided a outlet policy: no (todo)
7. implemented outputs: no (todo)
8. external working: no (todo)

• msvc project: version 0.1

at the moment the code for recognition is there and compiles without errors but actually doesn’t recognize anything. possible causes:

• wrong image format ( what kind of data doesarDetectMarker want?)
• wrong pattern loading procedure
• ??

about the image format: look in ARToolkit/include/AR/config.h you’ll see this:

/*------------------------------------------------------------*/
/*                                                            */
/*  For Linux, you should define one of below 3 input method  */
/*    AR_INPUT_V4L:     use of standard Video4Linux Library   */
/*    AR_INPUT_DV:      use of DV Camera                      */
/*    AR_INPUT_1394CAM: use of 1394 Digital Camara            */
/*                                                            */
/*------------------------------------------------------------*/
#ifdef __linux
#undef  AR_INPUT_V4L
#undef  AR_INPUT_DV
#undef  AR_INPUT_1394CAM

#ifdef AR_INPUT_V4L
#define  AR_PIX_FORMAT_BGR
#undef   AR_PIX_FORMAT_BGRA
#endif

#ifdef AR_INPUT_DV
#define  AR_PIX_FORMAT_RGB
#undef   AR_PIX_FORMAT_BGRA
#endif

#ifdef AR_INPUT_1394CAM
#define  AR_PIX_FORMAT_RGB
#endif

#undef   AR_BIG_ENDIAN
#define  AR_LITTLE_ENDIAN
#endif


/*------------------------------------------------------------*/
/*  For SGI                                                   */
/*------------------------------------------------------------*/
#ifdef __sgi
#define  AR_BIG_ENDIAN
#undef   AR_LITTLE_ENDIAN
#define  AR_PIX_FORMAT_ABGR
#endif

/*------------------------------------------------------------*/
/*  For Windows                                               */
/*------------------------------------------------------------*/
#ifdef _WIN32
#undef   AR_BIG_ENDIAN
#define  AR_LITTLE_ENDIAN
#define  AR_PIX_FORMAT_BGRA
//#define  AR_PIX_FORMAT_RGBA
#endif

/*------------------------------------------------------------*/
/*  For Mac OS X                                              */
/*------------------------------------------------------------*/
#if __APPLE_CC__
#define  AR_BIG_ENDIAN
#undef   AR_LITTLE_ENDIAN
#define  AR_PIX_FORMAT_RGBA
#endif

image format is a total mess!

however, arDetectMarker only really needs to know where the alpha channel is.. RGB=BGR?

ARToolkit/lib/src/AR/arGetTransMat2.c does not initialize some variables, i had to initialize them to 0. now i am able to call arGetTransMatCont.

• forum
• main page
• source code
• tutorials
• API
• forum post about including id-markers

important functions:

• the init function: where is it exactly?
• arVideoGetImage: we must make gem give artoolkit the same data structure as this one
• main loop: arDetectMarker and arGetTransMat