如何使用python在open cv中扩展一个线段

时间:2014-11-27 05:03:04

标签: python c++ algorithm python-2.7 opencv

我有一个线段的两个端点,我想扩展该线。 我通过这个网站找到了以下算法

          lengthAB = sqrt((a.x - b.x)^2 + (a.y - b.y)^2) 
          c.x = b.x + (b.x - a.x) / lengthAB * length;
          c.y = b.y + (b.y - a.y) / lengthAB * length;

但是当我在我的程序中实现它时,我无法获得输出。我需要int值,但cx和cy是浮动的。

![a(x,y)=(200,140),b(x,y)=(232,146)] [1]

  import numpy as np
  import cv2
  import math
  img = np.zeros((500,500,3), np.uint8)
  lenab = math.sqrt((200-232)**2+(158-146)**2)
  length = 100
  cx = 232 + (232-200) / lenab*length
  cy = 146 + (146-158) / lenab*length
  cv2.line(img,(200,158),(cx,cy),(33,322,122),3)
  cv2.imshow('Tha',img)
  cv2.waitKey(0)
  cv2.destroyAllWindows()

我的o / p屏幕:

      Traceback (most recent call last):
File "E:/Nan/inclined_line.py", line 9, in <module>
cv2.line(img,(200,158),(cx,cy),(33,322,122),3)
TypeError: integer argument expected, got float

2 个答案:

答案 0 :(得分:1)

分配给“点”变量时转换为整数

A=(100,100 )
B=(200,200 )
C=[200,200 ]
lenAB = math.sqrt(math.pow(A[0] - B[0], 2.0) + math.pow(A[1] - B[1], 2.0))

C[0] =int (B[0] + (B[0] - A[0]) / lenAB * 500)
C[1] = int(B[1] + (B[1] - A[1]) / lenAB * 500)
cv2.line(img,A,tuple(C),Colour_store.blue,1,1)

或在您的代码中。我真的不记得是否需要元组转换,但是“如果它没有损坏”

import numpy as np
import cv2
import math
img = np.zeros((500,500,3), np.uint8)
lenab = math.sqrt((200-232)**2+(158-146)**2)
length = 100

C=[200,200 ]
C[0] =int( 232 + (232-200) / lenab*length)
C[1] = int(146 + (146-158) / lenab*length)
cv2.line(img,(200,158),tuple(C),(33,322,122),3)
cv2.imshow('Tha',img)
cv2.waitKey(0)
cv2.destroyAllWindows()

答案 1 :(得分:0)

从您的错误中,您将浮点值传递给cv2.line。将float转换为整数,如下所示:

 cv2.line(img,(200,158),(int(math.floor(cx)),int(math.floor(cy))),(33,322,122),3)