opencv/samples/python/distrans.py
2019-03-20 18:32:34 +03:00

79 lines
1.6 KiB
Python
Executable File

#!/usr/bin/env python
'''
Distance transform sample.
Usage:
distrans.py [<image>]
Keys:
ESC - exit
v - toggle voronoi mode
'''
# Python 2/3 compatibility
from __future__ import print_function
import numpy as np
import cv2 as cv
from common import make_cmap
def main():
import sys
try:
fn = sys.argv[1]
except:
fn = 'fruits.jpg'
fn = cv.samples.findFile(fn)
img = cv.imread(fn, cv.IMREAD_GRAYSCALE)
if img is None:
print('Failed to load fn:', fn)
sys.exit(1)
cm = make_cmap('jet')
need_update = True
voronoi = False
def update(dummy=None):
global need_update
need_update = False
thrs = cv.getTrackbarPos('threshold', 'distrans')
mark = cv.Canny(img, thrs, 3*thrs)
dist, labels = cv.distanceTransformWithLabels(~mark, cv.DIST_L2, 5)
if voronoi:
vis = cm[np.uint8(labels)]
else:
vis = cm[np.uint8(dist*2)]
vis[mark != 0] = 255
cv.imshow('distrans', vis)
def invalidate(dummy=None):
global need_update
need_update = True
cv.namedWindow('distrans')
cv.createTrackbar('threshold', 'distrans', 60, 255, invalidate)
update()
while True:
ch = cv.waitKey(50)
if ch == 27:
break
if ch == ord('v'):
voronoi = not voronoi
print('showing', ['distance', 'voronoi'][voronoi])
update()
if need_update:
update()
print('Done')
if __name__ == '__main__':
print(__doc__)
main()
cv.destroyAllWindows()