39 lines
1.0 KiB
Python
39 lines
1.0 KiB
Python
import numpy as np
|
|
import cv2, cv
|
|
import video
|
|
import sys
|
|
|
|
try: fn = sys.argv[1]
|
|
except: fn = video.presets['chess']
|
|
|
|
cam = video.create_capture(fn)
|
|
ret, prev = cam.read()
|
|
#prev = cv2.pyrDown(prev)
|
|
prevgray = cv2.cvtColor(prev, cv.CV_BGR2GRAY)
|
|
|
|
def draw_flow(img, flow, step):
|
|
h, w = img.shape[:2]
|
|
y, x = map(np.ravel, np.mgrid[step/2:h:step, step/2:w:step])
|
|
f = flow[y,x]
|
|
x1 = x + f[:,0]
|
|
y1 = y + f[:,1]
|
|
#lines = np.int32( np.vstack([x, y, x1, y1]).T )
|
|
vis = cv2.cvtColor(img, cv.CV_GRAY2BGR)
|
|
#print lines
|
|
#cv2.polylines(vis, lines, 0, (0, 255, 0))
|
|
for x_, y_, x1_, y1_ in np.int32(zip(x, y, x1, y1)):
|
|
cv2.line(vis, (x_, y_), (x1_, y1_), (0, 255, 0))
|
|
return vis
|
|
|
|
while True:
|
|
ret, img = cam.read()
|
|
#img = cv2.pyrDown(img)
|
|
gray = cv2.cvtColor(img, cv.CV_BGR2GRAY)
|
|
flow = cv2.calcOpticalFlowFarneback(prevgray, gray, 0.5, 3, 15, 3, 5, 1.2, 0)
|
|
prevgray = gray
|
|
|
|
cv2.imshow('flow', draw_flow(gray, flow, 16))
|
|
if cv2.waitKey(5) == 27:
|
|
break
|
|
|