in chapter 3 the hough-line

[yqtaowhu]

this is some wrong with me,i run you code ,but this is not right for you example,have no line int the picture,
i do not know what is wrong
please tell me ,thank you very much!

[techfort]

hey @yqtaowhu can you elaborate a bit? what appears to be wrong, and in what file?

[yqtaowhu]

@techfort i very happy you can reply me , in the chaper3 ,and Hough_Lines.py to detect a line
`import cv2
import numpy as np

img = cv2.imread('lines.jpg')
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
edges = cv2.Canny(gray,50,120)
minLineLength = 20
maxLineGap = 0
lines = cv2.HoughLinesP(edges,1,np.pi/180,50,minLineLength,maxLineGap)
dst = edges
for x1,y1,x2,y2 in lines[0]:
cv2.line(edges,(x1,y1),(x2,y2),(255,0,0),2)

cv2.imshow("edges", edges)
cv2.imshow("lines",img)
cv2.waitKey()
cv2.destroyAllWindows()`
and the result not show a line detect , it is only the origin picture , i dont know why,i have not change your code .
Look forward to your reply

[Micah2015]

I changed lines[0] to follows
for line in lines:
for x1,y1,x2,y2 in line:
cv2.line(img,(x1,y1),(x2,y2),(0,255,0),5)