--- a/scripts/init-tracking.py	Tue Jun 05 14:33:31 2018 -0400
+++ b/scripts/init-tracking.py	Tue Jun 05 17:02:28 2018 -0400
@@ -11,6 +11,7 @@
 parser = argparse.ArgumentParser(description='The program initilizes the files for tracking: copy tracking.cfg, sets up with the video filename, generates a frame image (frame.png) and prints the next commands')
 
 parser.add_argument('-i', dest = 'videoFilename', help = 'filename of the video sequence', required = True)
+parser.add_argument('-n', dest = 'nFrames', help = 'number of frames to extract', type = int)
 
 args = parser.parse_args()
 
@@ -45,12 +46,19 @@
         print('Configuration file classifier.cfg successfully copied to the current directory')
         
 # extract image from video
-image = getImagesFromVideo(args.videoFilename, saveImage = True, outputPrefix = 'frame')
+if args.nFrames is not None:
+    image = getImagesFromVideo(args.videoFilename, 0, args.nFrames, saveImage = True, outputPrefix = 'frame')
+else:
+    image = getImagesFromVideo(args.videoFilename, saveImage = True, outputPrefix = 'frame')
 print('first video frame successfully copied to the current directory')
 
 # next commands
-print('--------------------------------------\nHere are a sample of the next command to compute the homography,\ntrack features, group them in objects and display object trajectories\n--------------------------------------')
-print('compute_homography -i [frame.png] -w [world_image] -n [npoints] -u [unit_per_pixel]')
+print('''--------------------------------------
+Here are a sample of the next command to compute the homography,
+track features, group them in objects and display object trajectories
+--------------------------------------''')
+print('compute-homography -i [frame.png] -w [world_image] -n [npoints] -u [unit_per_pixel]')
+print('(beware of camera distortion)')
 print('feature-based-tracking tracking.cfg --tf')
 print('feature-based-tracking tracking.cfg --gf')
 print('display-trajectories --cfg tracking.cfg -t object')