mirror of https://github.com/opencv/opencv.git
Open Source Computer Vision Library
https://opencv.org/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
86 lines
2.3 KiB
86 lines
2.3 KiB
#!/usr/bin/env 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 = 0xFF & 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] |
|
cv2.destroyAllWindows() |
|
|
|
|