In this Video Tutorial we show how a camera on a pan/tilt control system can be programmed to search for an object of interest, and then track it when found. Our system has two independent camera systems, and each can track a separate item of interest independently. The code is written in python, using the OpenCV library. The video takes you through the lesson step-by-step, and then the code is included below for your convenience.
If you want to play along at home, we are using the Jetson Xavier NX, which you can pick up HERE. You will also need to of the bracket/servo kits, which you can get HERE, and then two Raspberry Pi Version two cameras, available HERE.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 | import cv2 import numpy as np import time from adafruit_servokit import ServoKit print(cv2.__version__) timeMark=time.time() dtFIL=0 scanRight=True scanLeft=True def nothing(x): pass cv2.namedWindow('TrackBars') cv2.moveWindow('TrackBars',1320,0) cv2.createTrackbar('hueLower', 'TrackBars',100,179,nothing) cv2.createTrackbar('hueUpper', 'TrackBars',116,179,nothing) cv2.createTrackbar('satLow', 'TrackBars',160,255,nothing) cv2.createTrackbar('satHigh', 'TrackBars',255,255,nothing) cv2.createTrackbar('valLow', 'TrackBars',150,255,nothing) cv2.createTrackbar('valHigh', 'TrackBars',255,255,nothing) cv2.namedWindow('TrackBars2') cv2.moveWindow('TrackBars2',1100,0) cv2.createTrackbar('hueLower2', 'TrackBars2',150,179,nothing) cv2.createTrackbar('hueUpper2', 'TrackBars2',170,179,nothing) cv2.createTrackbar('satLow2', 'TrackBars2',160,255,nothing) cv2.createTrackbar('satHigh2', 'TrackBars2',255,255,nothing) cv2.createTrackbar('valLow2', 'TrackBars2',150,255,nothing) cv2.createTrackbar('valHigh2', 'TrackBars2',255,255,nothing) kit=ServoKit(channels=16) tilt1=90 pan1=90 tilt2=90 pan2=90 dPan1=1 dPan2=1 dTilt1=10 dTilt2=10 kit.servo[0].angle=pan1 kit.servo[1].angle=tilt1 kit.servo[2].angle=pan2 kit.servo[3].angle=tilt2 width=720 height=480 flip=2 font=cv2.FONT_HERSHEY_SIMPLEX camSet1='nvarguscamerasrc sensor-id=0 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True' camSet2='nvarguscamerasrc sensor-id=1 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True' #camSet='nvarguscamerasrc sensor-id=0 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink' #camSet ='v4l2src device=/dev/video1 ! video/x-raw,width='+str(width)+',height='+str(height)+',framerate=20/1 ! videoconvert ! appsink' cam1=cv2.VideoCapture(camSet1) cam2=cv2.VideoCapture(camSet2) while True: _, frame1 = cam1.read() _, frame2 = cam2.read() hsv1=cv2.cvtColor(frame1,cv2.COLOR_BGR2HSV) hsv2=cv2.cvtColor(frame2,cv2.COLOR_BGR2HSV) hueLow=cv2.getTrackbarPos('hueLower', 'TrackBars') hueUp=cv2.getTrackbarPos('hueUpper', 'TrackBars') Ls=cv2.getTrackbarPos('satLow', 'TrackBars') Us=cv2.getTrackbarPos('satHigh', 'TrackBars') Lv=cv2.getTrackbarPos('valLow', 'TrackBars') Uv=cv2.getTrackbarPos('valHigh', 'TrackBars') l_b=np.array([hueLow,Ls,Lv]) u_b=np.array([hueUp,Us,Uv]) hueLow2=cv2.getTrackbarPos('hueLower2', 'TrackBars2') hueUp2=cv2.getTrackbarPos('hueUpper2', 'TrackBars2') Ls2=cv2.getTrackbarPos('satLow2', 'TrackBars2') Us2=cv2.getTrackbarPos('satHigh2', 'TrackBars2') Lv2=cv2.getTrackbarPos('valLow2', 'TrackBars2') Uv2=cv2.getTrackbarPos('valHigh2', 'TrackBars2') l_b2=np.array([hueLow2,Ls2,Lv2]) u_b2=np.array([hueUp2,Us2,Uv2]) FGmask1=cv2.inRange(hsv1,l_b,u_b) FGmask2=cv2.inRange(hsv2,l_b2,u_b2) cv2.imshow('FGmask1',FGmask1) cv2.moveWindow('FGmask1',0,0) cv2.imshow('FGmask2',FGmask2) cv2.moveWindow('FGmask2',350,0) contours1,_ = cv2.findContours(FGmask1,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE) contours1=sorted(contours1,key=lambda x:cv2.contourArea(x),reverse=True) for cnt in contours1: area=cv2.contourArea(cnt) (x,y,w,h)=cv2.boundingRect(cnt) if area>=100: scanLeft=False cv2.rectangle(frame1,(x,y),(x+w,y+h),(0,255,255),3) objX=x+w/2 objY=y+h/2 errorPan1=objX-width/2 errorTilt1=objY-height/2 if abs(errorPan1)>15: pan1=pan1+errorPan1/40 if abs(errorTilt1)>15: tilt1=tilt1-errorTilt1/40 if pan1>180: pan1=180 print('Pan Out of Range') if pan1<0: pan1=0 print('Pan Out of Range') if tilt1>180: tilt1=180 print('Tilt Out of Range') if tilt1<0: tilt1=0 kit.servo[2].angle=pan1 kit.servo[3].angle=tilt1 break contours2,_ = cv2.findContours(FGmask2,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE) contours2=sorted(contours2,key=lambda x:cv2.contourArea(x),reverse=True) for cnt in contours2: area=cv2.contourArea(cnt) (x,y,w,h)=cv2.boundingRect(cnt) if area>=100: scanRight=False cv2.rectangle(frame2,(x,y),(x+w,y+h),(0,255,255),3) objX=x+w/2 objY=y+h/2 errorPan2=objX-width/2 errorTilt2=objY-height/2 if abs(errorPan2)>15: pan2=pan2+errorPan2/40 if abs(errorTilt2)>15: tilt2=tilt2-errorTilt2/40 if pan2>180: pan2=180 print('Pan Out of Range') if pan2<0: pan2=0 print('Pan Out of Range') if tilt2>180: tilt2=180 print('Tilt Out of Range') if tilt2<0: tilt2=0 kit.servo[0].angle=pan2 kit.servo[1].angle=tilt2 break if scanLeft==True: if pan1>=179: dPan1=abs(dPan1)*(-1) if pan1<=1: dPan1=abs(dPan1) if pan1>=179 or pan1<=1: if tilt1>=170: dTilt1=abs(dTilt1)*(-1) if tilt1<=10: dTilt1=abs(dTilt1) tilt1=tilt1+dTilt1 pan1=pan1+dPan1 kit.servo[2].angle=pan1 kit.servo[3].angle=tilt1 scanLeft=True if scanRight==True: if pan2>=179: dPan2=abs(dPan2)*(-1) if pan2<=1: dPan2=abs(dPan2) if pan2>=179 or pan2<=1: if tilt2>=170: dTilt2=abs(dTilt2)*(-1) if tilt2<=10: dTilt2=abs(dTilt2) tilt2=tilt2+dTilt2 pan2=pan2+dPan2 kit.servo[0].angle=pan2 kit.servo[1].angle=tilt2 scanRight=True frame3=np.hstack((frame1,frame2)) dt=time.time()-timeMark timeMark=time.time() dtFIL=.9*dtFIL + .1*dt fps=1/dtFIL cv2.rectangle(frame3,(0,0),(150,40),(0,0,255),-1) cv2.putText(frame3,'fps: '+str(round(fps,1)),(0,30),font,1,(0,255,255),2) #cv2.imshow('myCam1',frame1) #cv2.imshow('myCam2',frame2) cv2.imshow('comboCam',frame3) cv2.moveWindow('comboCam',0,450) if cv2.waitKey(1)==ord('q'): break cam1.release() cam2.release() cv2.destroyAllWindows() |