import numpy as np
import cv2
cap = cv2.VideoCapture("slow.avi")
while not cap.isOpened():
cap = cv2.VideoCapture("slow.avi")
cv2.waitKey(1000)
print "Wait for the header"
# params for ShiTomasi corner detection
feature_params = dict(maxCorners = 100,
qualityLevel = 0.3,
minDistance = 7,
blockSize = 7)
# Parameters for lucas kanade optical flow
lk_params = dict(winSize = (15,15),
maxLevel = 2,
criteria = (cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 0.03))
# Create some random colors
color = np.random.randint(0,255,(100,3))
# Take first frame and find corners in it
ret, old_frame = cap.read()
old_gray = cv2.cvtColor(old_frame, cv2.COLOR_BGR2GRAY)
p0 = cv2.goodFeaturesToTrack(old_gray, mask = None, **feature_params)
#print old_frame
# Create a mask image for drawing purposes
mask = np.zeros_like(old_frame)
while(1):
ret,frame = cap.read()
frame_gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
# calculate optical flow
p1, st, err = cv2.calcOpticalFlowPyrLK(old_gray, frame_gray, p0, None, **lk_params)
# Select good points
good_new = p1[st==1]
good_old = p0[st==1]
# draw the tracks
for i,(new,old) in enumerate(zip(good_new,good_old)):
a,b = new.ravel()
c,d = old.ravel()
mask = cv2.line(mask, (a,b),(c,d), color[i].tolist(), 2)
frame = cv2.circle(frame,(a,b),5,color[i].tolist(),-1)
img = cv2.add(frame,mask)
cv2.imshow('frame',img)
k = cv2.waitKey(30) & 0xff
if k == 27:
break
# Now update the previous frame and previous points
old_gray = frame_gray.copy()
p0 = good_new.reshape(-1,1,2)
cv2.destroyAllWindows()
cap.release()
我抄光流示例代码http://docs.opencv.org/trunk/doc/py_tutorials/py_video/py_lucas_kanade/py_lucas_kanade.html但不工作,让我试图修复该错误消息,但便无法OpenCV的光流的示例代码错误
line 56, in <module>
cv2.imshow('frame',img)
error: ..\..\..\opencv-2.4.8.1\modules\highgui\src\window.cpp:269:
error: (-215) size.width>0 && size.height>0 in function cv::imshow
难道可以打开AVI文件没有像它 – Horizon
检查从cap.read的RETVAL(),您正在忽略。如果它是假的,你不应该在你到达电影结尾或其他出错时继续。 –