mirror of
https://github.com/opencv/opencv.git
synced 2024-11-30 14:29:49 +08:00
84 lines
2.4 KiB
Python
84 lines
2.4 KiB
Python
import numpy as np
|
|
import cv2
|
|
import video
|
|
|
|
help_message = '''
|
|
USAGE: opt_flow.py [<video_source>]
|
|
|
|
Keys:
|
|
1 - toggle HSV flow visualization
|
|
2 - toggle glitch
|
|
|
|
'''
|
|
|
|
def draw_flow(img, flow, step=16):
|
|
h, w = img.shape[:2]
|
|
y, x = np.mgrid[step/2:h:step, step/2:w:step].reshape(2,-1)
|
|
fx, fy = flow[y,x].T
|
|
lines = np.vstack([x, y, x+fx, y+fy]).T.reshape(-1, 2, 2)
|
|
lines = np.int32(lines + 0.5)
|
|
vis = cv2.cvtColor(img, cv2.COLOR_GRAY2BGR)
|
|
cv2.polylines(vis, lines, 0, (0, 255, 0))
|
|
for (x1, y1), (x2, y2) in lines:
|
|
cv2.circle(vis, (x1, y1), 1, (0, 255, 0), -1)
|
|
return vis
|
|
|
|
def draw_hsv(flow):
|
|
h, w = flow.shape[:2]
|
|
fx, fy = flow[:,:,0], flow[:,:,1]
|
|
ang = np.arctan2(fy, fx) + np.pi
|
|
v = np.sqrt(fx*fx+fy*fy)
|
|
hsv = np.zeros((h, w, 3), np.uint8)
|
|
hsv[...,0] = ang*(180/np.pi/2)
|
|
hsv[...,1] = 255
|
|
hsv[...,2] = np.minimum(v*4, 255)
|
|
bgr = cv2.cvtColor(hsv, cv2.COLOR_HSV2BGR)
|
|
return bgr
|
|
|
|
def warp_flow(img, flow):
|
|
h, w = flow.shape[:2]
|
|
flow = -flow
|
|
flow[:,:,0] += np.arange(w)
|
|
flow[:,:,1] += np.arange(h)[:,np.newaxis]
|
|
res = cv2.remap(img, flow, None, cv2.INTER_LINEAR)
|
|
return res
|
|
|
|
if __name__ == '__main__':
|
|
import sys
|
|
print help_message
|
|
try: fn = sys.argv[1]
|
|
except: fn = 0
|
|
|
|
cam = video.create_capture(fn)
|
|
ret, prev = cam.read()
|
|
prevgray = cv2.cvtColor(prev, cv2.COLOR_BGR2GRAY)
|
|
show_hsv = False
|
|
show_glitch = False
|
|
cur_glitch = prev.copy()
|
|
|
|
while True:
|
|
ret, img = cam.read()
|
|
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
|
|
flow = cv2.calcOpticalFlowFarneback(prevgray, gray, 0.5, 3, 15, 3, 5, 1.2, 0)
|
|
prevgray = gray
|
|
|
|
cv2.imshow('flow', draw_flow(gray, flow))
|
|
if show_hsv:
|
|
cv2.imshow('flow HSV', draw_hsv(flow))
|
|
if show_glitch:
|
|
cur_glitch = warp_flow(cur_glitch, flow)
|
|
cv2.imshow('glitch', cur_glitch)
|
|
|
|
ch = cv2.waitKey(5)
|
|
if ch == 27:
|
|
break
|
|
if ch == ord('1'):
|
|
show_hsv = not show_hsv
|
|
print 'HSV flow visualization is', ['off', 'on'][show_hsv]
|
|
if ch == ord('2'):
|
|
show_glitch = not show_glitch
|
|
if show_glitch:
|
|
cur_glitch = img.copy()
|
|
print 'glitch is', ['off', 'on'][show_glitch]
|
|
|