Update to 2.0.0 tree from current Fremantle build

[opencv] / samples / swig_python / kalman.py

diff --git a/samples/swig_python/kalman.py b/samples/swig_python/kalman.py
new file mode 100755 (executable)
index 0000000..99d9bf3
--- /dev/null
+++ b/samples/swig_python/kalman.py
@@ -0,0 +1,92 @@
+#!/usr/bin/python
+""" 
+   Tracking of rotating point.
+   Rotation speed is constant.
+   Both state and measurements vectors are 1D (a point angle),
+   Measurement is the real point angle + gaussian noise.
+   The real and the estimated points are connected with yellow line segment,
+   the real and the measured points are connected with red line segment.
+   (if Kalman filter works correctly,
+    the yellow segment should be shorter than the red one).
+   Pressing any key (except ESC) will reset the tracking with a different speed.
+   Pressing ESC will stop the program.
+"""
+from opencv.cv import *
+from opencv.highgui import *
+from math import cos, sin, sqrt
+
+if __name__ == "__main__":
+    A = [ [1, 1], [0, 1] ]
+    
+    img = cvCreateImage( cvSize(500,500), 8, 3 )
+    kalman = cvCreateKalman( 2, 1, 0 )
+    state = cvCreateMat( 2, 1, CV_32FC1 )  # (phi, delta_phi)
+    process_noise = cvCreateMat( 2, 1, CV_32FC1 )
+    measurement = cvCreateMat( 1, 1, CV_32FC1 )
+    rng = cvRNG(-1)
+    code = -1L
+
+    cvZero( measurement )
+    cvNamedWindow( "Kalman", 1 )
+
+    while True:
+        cvRandArr( rng, state, CV_RAND_NORMAL, cvRealScalar(0), cvRealScalar(0.1) )
+        
+        kalman.transition_matrix[:] = 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))
+        cvRandArr( rng, kalman.state_post, CV_RAND_NORMAL, cvRealScalar(0), cvRealScalar(0.1) )
+        
+        while True:
+            def calc_point(angle):
+                return cvPoint( cvRound(img.width/2 + img.width/3*cos(angle)),
+                         cvRound(img.height/2 - img.width/3*sin(angle))) 
+
+            state_angle = state[0] 
+            state_pt = calc_point(state_angle)
+            
+            prediction = cvKalmanPredict( kalman )
+            predict_angle = prediction[0,0] 
+            predict_pt = calc_point(predict_angle)
+
+            cvRandArr( rng, measurement, CV_RAND_NORMAL, cvRealScalar(0),
+                       cvRealScalar(sqrt(kalman.measurement_noise_cov[0,0])) )
+
+            # generate measurement 
+            cvMatMulAdd( kalman.measurement_matrix, state, measurement, measurement )
+
+            measurement_angle = measurement[0,0]
+            measurement_pt = calc_point(measurement_angle)
+            
+            # plot points 
+            def draw_cross( center, color, d ):                                 
+                cvLine( img, cvPoint( center.x - d, center.y - d ),                
+                             cvPoint( center.x + d, center.y + d ), color, 1, CV_AA, 0) 
+                cvLine( img, cvPoint( center.x + d, center.y - d ),                
+                             cvPoint( center.x - d, center.y + d ), color, 1, CV_AA, 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, measurement_pt, CV_RGB(255,0,0), 3, CV_AA, 0 )
+            cvLine( img, state_pt, predict_pt, CV_RGB(255,255,0), 3, CV_AA, 0 )
+            
+            cvKalmanCorrect( kalman, measurement )
+
+            cvRandArr( rng, process_noise, CV_RAND_NORMAL, cvRealScalar(0),
+                       cvRealScalar(sqrt(kalman.process_noise_cov[0,0])))
+            cvMatMulAdd( kalman.transition_matrix, state, process_noise, state )
+
+            cvShowImage( "Kalman", img )
+            
+            code = str(cvWaitKey( 100 ))
+            if( code != '-1'):
+                break
+            
+        if( code == '\x1b' or code == 'q' or code == 'Q' ):
+            break
+    
+    cvDestroyWindow("Kalman")