opencv/samples/python2/edge.py

55 lines
1.1 KiB
Python
Executable File

#!/usr/bin/env python
'''
This sample demonstrates Canny edge detection.
Usage:
edge.py [<video source>]
Trackbars control edge thresholds.
'''
# Python 2/3 compatibility
from __future__ import print_function
import cv2
# relative module
import video
# built-in module
import sys
if __name__ == '__main__':
print(__doc__)
try:
fn = sys.argv[1]
except:
fn = 0
def nothing(*arg):
pass
cv2.namedWindow('edge')
cv2.createTrackbar('thrs1', 'edge', 2000, 5000, nothing)
cv2.createTrackbar('thrs2', 'edge', 4000, 5000, nothing)
cap = video.create_capture(fn)
while True:
flag, img = cap.read()
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
thrs1 = cv2.getTrackbarPos('thrs1', 'edge')
thrs2 = cv2.getTrackbarPos('thrs2', 'edge')
edge = cv2.Canny(gray, thrs1, thrs2, apertureSize=5)
vis = img.copy()
vis /= 2
vis[edge != 0] = (0, 255, 0)
cv2.imshow('edge', vis)
ch = cv2.waitKey(5) & 0xFF
if ch == 27:
break
cv2.destroyAllWindows()