Bonjour,
Dans le cadre de mon stage on me demande d'implementer un filtre de Kalman a l'aide d'OpenCv. Mon probleme c'est que deja j'arrive pas a me servir du filtre deja implemente sur OpenCv. Si quelqu'un pouvait m'expliquer a quoi correspondent les differents parametres, comment les initialiser... je vous serait tres reconnaissant.
Je me sers de l'exemple present dans le manuel de reference OpenCv mais je n'arrive meme pas a le comprendre...
Code : Sélectionner tout - Visualiser dans une fenêtre à part
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#include "cv.h"
#include "highgui.h"
#include <math.h>
int main(int argc, char** argv)
{
	/* A matrix data */
	const float A[] = { 1, 1, 0, 1 };
	IplImage* img = cvCreateImage( cvSize(500,500), 8, 3 );
	CvKalman* kalman = cvCreateKalman( 2, 1, 0 );
	/* state is (phi, delta_phi) - angle and angle increment */
	CvMat* state = cvCreateMat( 2, 1, CV_32FC1 );
	CvMat* process_noise = cvCreateMat( 2, 1, CV_32FC1 );
	/* only phi (angle) is measured */
	CvMat* measurement = cvCreateMat( 1, 1, CV_32FC1 );
	CvRandState rng;
	int code = -1;
	cvRandInit( &rng, 0, 1, -1, CV_RAND_UNI );
	cvZero( measurement );
	cvNamedWindow( "Kalman", 1 );
	for(;;)
	{
		cvRandSetRange( &rng, 0, 0.1, 0 );
		rng.disttype = CV_RAND_NORMAL;
		cvRand( &rng, state );
		memcpy( kalman->transition_matrix->data.fl, A, sizeof(A));
		cvSetIdentity( kalman->measurement_matrix, cvRealScalar(1) );
		cvSetIdentity( kalman->process_noise_cov, cvRealScalar(1e-5) );
		cvSetIdentity( kalman->measurement_noise_cov, cvRealScalar(1e-1) );
		cvSetIdentity( kalman->error_cov_post, cvRealScalar(1));
		/* choose random initial state */
		cvRand( &rng, kalman->state_post );
		rng.disttype = CV_RAND_NORMAL;
		for(;;)
		{
			#define calc_point(angle) \
			cvPoint( cvRound(img->width/2 + img->width/3*cos(angle)), \
			cvRound(img->height/2 - img->width/3*sin(angle)))
			float state_angle = state->data.fl[0];
			CvPoint state_pt = calc_point(state_angle);
			/* predict point position */
			const CvMat* prediction = cvKalmanPredict( kalman, 0 );
			float predict_angle = prediction->data.fl[0];
			CvPoint predict_pt = calc_point(predict_angle);
			float measurement_angle;
			CvPoint measurement_pt;
			cvRandSetRange( &rng,
			0,
			sqrt(kalman->measurement_noise_cov->data.fl[0]),
			0 );
			cvRand( &rng, measurement );
			/* generate measurement */
			cvMatMulAdd( kalman->measurement_matrix, state, measurement, measurement );
			measurement_angle = measurement->data.fl[0];
			measurement_pt = calc_point(measurement_angle);
			/* plot points */
			#define draw_cross( center, color, d ) \
			cvLine( img, cvPoint( center.x - d, center.y - d ), \
			cvPoint( center.x + d, center.y + d ), \
			color, 1, 0 ); \
			cvLine( img, cvPoint( center.x + d, center.y - d ), \
			cvPoint( center.x - d, center.y + d ), \
			color, 1, 0 )
			cvZero( img );
			draw_cross( state_pt, CV_RGB(255,255,255), 3 );
			draw_cross( measurement_pt, CV_RGB(255,0,0), 3 );
			draw_cross( predict_pt, CV_RGB(0,255,0), 3 );
			cvLine( img, state_pt, predict_pt, CV_RGB(255,255,0), 3, 0 );
			/* adjust Kalman filter state */
			cvKalmanCorrect( kalman, measurement );
			cvRandSetRange( &rng,
			0,
			sqrt(kalman->process_noise_cov->data.fl[0]),
			0 );
			cvRand( &rng, process_noise );
			cvMatMulAdd( kalman->transition_matrix,
			state,
			process_noise,
			state );
			cvShowImage( "Kalman", img );
			code = cvWaitKey( 100 );
			if( code > 0 ) /* break current simulation by pressing a key */
			break;
		}
		if( code == 27 ) /* exit by ESCAPE */
		break;
	}
	return 0;
}
Quel est la croix qui represente le point traque et que represente le measurement?
Merci d'avance.