1 #!/usr/bin/env python 2 3 ''' 4 Camshift tracker 5 ================ 6 7 This is a demo that shows mean-shift based tracking 8 You select a color objects such as your face and it tracks it. 9 This reads from video camera (0 by default, or the camera number the user enters) 10 11 http://www.robinhewitt.com/research/track/camshift.html 12 13 Usage: 14 ------ 15 camshift.py [<video source>] 16 17 To initialize tracking, select the object with mouse 18 19 Keys: 20 ----- 21 ESC - exit 22 b - toggle back-projected probability visualization 23 ''' 24 25 import numpy as np 26 import cv2 27 28 # local module 29 import video 30 31 32 class App(object): 33 def __init__(self, video_src): 34 self.cam = video.create_capture(video_src) 35 ret, self.frame = self.cam.read() 36 cv2.namedWindow('camshift') 37 cv2.setMouseCallback('camshift', self.onmouse) 38 39 self.selection = None 40 self.drag_start = None 41 self.tracking_state = 0 42 self.show_backproj = False 43 44 def onmouse(self, event, x, y, flags, param): 45 x, y = np.int16([x, y]) # BUG 46 if event == cv2.EVENT_LBUTTONDOWN: 47 self.drag_start = (x, y) 48 self.tracking_state = 0 49 if self.drag_start: 50 if flags & cv2.EVENT_FLAG_LBUTTON: 51 h, w = self.frame.shape[:2] 52 xo, yo = self.drag_start 53 x0, y0 = np.maximum(0, np.minimum([xo, yo], [x, y])) 54 x1, y1 = np.minimum([w, h], np.maximum([xo, yo], [x, y])) 55 self.selection = None 56 if x1-x0 > 0 and y1-y0 > 0: 57 self.selection = (x0, y0, x1, y1) 58 else: 59 self.drag_start = None 60 if self.selection is not None: 61 self.tracking_state = 1 62 63 def show_hist(self): 64 bin_count = self.hist.shape[0] 65 bin_w = 24 66 img = np.zeros((256, bin_count*bin_w, 3), np.uint8) 67 for i in xrange(bin_count): 68 h = int(self.hist[i]) 69 cv2.rectangle(img, (i*bin_w+2, 255), ((i+1)*bin_w-2, 255-h), (int(180.0*i/bin_count), 255, 255), -1) 70 img = cv2.cvtColor(img, cv2.COLOR_HSV2BGR) 71 cv2.imshow('hist', img) 72 73 def run(self): 74 while True: 75 ret, self.frame = self.cam.read() 76 vis = self.frame.copy() 77 hsv = cv2.cvtColor(self.frame, cv2.COLOR_BGR2HSV) 78 mask = cv2.inRange(hsv, np.array((0., 60., 32.)), np.array((180., 255., 255.))) 79 80 if self.selection: 81 x0, y0, x1, y1 = self.selection 82 self.track_window = (x0, y0, x1-x0, y1-y0) 83 hsv_roi = hsv[y0:y1, x0:x1] 84 mask_roi = mask[y0:y1, x0:x1] 85 hist = cv2.calcHist( [hsv_roi], [0], mask_roi, [16], [0, 180] ) 86 cv2.normalize(hist, hist, 0, 255, cv2.NORM_MINMAX); 87 self.hist = hist.reshape(-1) 88 self.show_hist() 89 90 vis_roi = vis[y0:y1, x0:x1] 91 cv2.bitwise_not(vis_roi, vis_roi) 92 vis[mask == 0] = 0 93 94 if self.tracking_state == 1: 95 self.selection = None 96 prob = cv2.calcBackProject([hsv], [0], self.hist, [0, 180], 1) 97 prob &= mask 98 term_crit = ( cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1 ) 99 track_box, self.track_window = cv2.CamShift(prob, self.track_window, term_crit) 100 101 if self.show_backproj: 102 vis[:] = prob[...,np.newaxis] 103 try: 104 cv2.ellipse(vis, track_box, (0, 0, 255), 2) 105 except: 106 print track_box 107 108 cv2.imshow('camshift', vis) 109 110 ch = 0xFF & cv2.waitKey(5) 111 if ch == 27: 112 break 113 if ch == ord('b'): 114 self.show_backproj = not self.show_backproj 115 cv2.destroyAllWindows() 116 117 118 if __name__ == '__main__': 119 import sys 120 try: 121 video_src = sys.argv[1] 122 except: 123 video_src = 0 124 print __doc__ 125 App(video_src).run() 126
