Hello, I am trying to run the meanshift code from the opencv tutorial, except I am capturing my video from the webcam. When I try to draw a rectangle on the image however, I get the following error:
error: (-215) size.width>0 && size.height>0
Which is strange because I know that the height and width are positive. Any suggestions? Here is the code incase anyone needs it. Thanks in advance!
import numpy as np import cv2
cap = cv2.VideoCapture(0)
take first frame of the video
ret,frame = cap.read() print "HI" print frame
setup initial location of window
r,h,c,w = 250,90,400,125 # simply hardcoded the values track_window = (c,r,w,h)
set up the ROI for tracking
roi = frame[r:r+h, c:c+w] print roi hsv_roi = cv2.cvtColor(roi, cv2.COLOR_BGR2HSV) mask = cv2.inRange(hsv_roi, np.array((0., 60.,32.)), np.array((180.,255.,255.))) roi_hist = cv2.calcHist([hsv_roi],[0],mask,[180],[0,180]) cv2.normalize(roi_hist,roi_hist,0,255,cv2.NORM_MINMAX)
Setup the termination criteria, either 10 iteration or move by atleast 1 pt
term_crit = ( cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1 )
while(1): ret ,frame = cap.read() print frame
if ret == True:
hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
dst = cv2.calcBackProject([hsv],[0],roi_hist,[0,180],1)
# apply meanshift to get the new location
ret, track_window = cv2.meanShift(dst, track_window, term_crit)
# Draw it on image
x,y,w,h = track_window
img2 = cv2.rectangle(frame, (x,y), (x+w,y+h), 255,2)
cv2.imshow('img2',img2)
img2 = cv2.circle(frame, (200,200),50, 255,2)
k = cv2.waitKey(60) & 0xff
if k == 27:
break
else:
cv2.imwrite(chr(k)+".jpg",img2)
else:
break
cv2.destroyAllWindows() cap.release()
