opencv/samples/python/houghlines.py

58 lines
2.0 KiB
Python
Executable File

#!/usr/bin/python
# This is a standalone program. Pass an image name as a first parameter of the program.
import sys
from math import sin, cos, sqrt, pi
import cv
import urllib2
# toggle between CV_HOUGH_STANDARD and CV_HOUGH_PROBILISTIC
USE_STANDARD = True
if __name__ == "__main__":
if len(sys.argv) > 1:
filename = sys.argv[1]
src = cv.LoadImage(filename, cv.CV_LOAD_IMAGE_GRAYSCALE)
else:
url = 'https://code.ros.org/svn/opencv/trunk/opencv/doc/pics/building.jpg'
filedata = urllib2.urlopen(url).read()
imagefiledata = cv.CreateMatHeader(1, len(filedata), cv.CV_8UC1)
cv.SetData(imagefiledata, filedata, len(filedata))
src = cv.DecodeImageM(imagefiledata, cv.CV_LOAD_IMAGE_GRAYSCALE)
cv.NamedWindow("Source", 1)
cv.NamedWindow("Hough", 1)
while True:
dst = cv.CreateImage(cv.GetSize(src), 8, 1)
color_dst = cv.CreateImage(cv.GetSize(src), 8, 3)
storage = cv.CreateMemStorage(0)
lines = 0
cv.Canny(src, dst, 50, 200, 3)
cv.CvtColor(dst, color_dst, cv.CV_GRAY2BGR)
if USE_STANDARD:
lines = cv.HoughLines2(dst, storage, cv.CV_HOUGH_STANDARD, 1, pi / 180, 100, 0, 0)
for (rho, theta) in lines[:100]:
a = cos(theta)
b = sin(theta)
x0 = a * rho
y0 = b * rho
pt1 = (cv.Round(x0 + 1000*(-b)), cv.Round(y0 + 1000*(a)))
pt2 = (cv.Round(x0 - 1000*(-b)), cv.Round(y0 - 1000*(a)))
cv.Line(color_dst, pt1, pt2, cv.RGB(255, 0, 0), 3, 8)
else:
lines = cv.HoughLines2(dst, storage, cv.CV_HOUGH_PROBABILISTIC, 1, pi / 180, 50, 50, 10)
for line in lines:
cv.Line(color_dst, line[0], line[1], cv.CV_RGB(255, 0, 0), 3, 8)
cv.ShowImage("Source", src)
cv.ShowImage("Hough", color_dst)
k = cv.WaitKey(0) % 0x100
if k == ord(' '):
USE_STANDARD = not USE_STANDARD
if k == 27:
break