TypeError:找不到必需参数'outImg'(pos 6)

Question

当我运行我的python代码

import numpy as np
import cv2
import matplotlib.pyplot as plt

img1 = cv2.imread('/home/shar/home.jpg',0)          # queryImage
img2 = cv2.imread('/home/shar/home2.jpg',0) # trainImage

# Initiate SIFT detector

sift = cv2.xfeatures2d.SIFT_create()
# find the keypoints and descriptors with SIFT
kp1, des1 = sift.detectAndCompute(img1,None)
kp2, des2 = sift.detectAndCompute(img2,None)

# BFMatcher with default params
bf = cv2.BFMatcher()
matches = bf.knnMatch(des1,des2, k=2)

# Apply ratio test
good = []
for m,n in matches:
    if m.distance < 0.75*n.distance:
        good.append([m])

# cv2.drawMatchesKnn expects list of lists as matches.
img3 = cv2.drawMatchesKnn(img1,kp1,img2,kp2,good,flags=2)


plt.imshow(img3),plt.show()

从这条线

img3 = cv2.drawMatchesKnn(img1,kp1,img2,kp2,good,flags=2)

我收到这个错误

TypeError: Required argument 'outImg' (pos 6) not found

我正在使用python3和opencv3

Answer 1

你似乎是下面这个教程页面(基于代码,你曾表示这和你的两个相关问题1,2).

该函数文档是在这里(虽然我注意到它仍然是标有"测试版"),并暗示outImg是可选的.但是,python错误消息是显式的 - 位置6需要一个参数,它outImg在函数签名中命名.我怀疑文档可能与代码要求不完全一致.它显示了的签名C++代码,该蟒结合正在呼叫具有用于没有缺省值outImg,所以需要提供这样的说法.

请注意,您可以通过查看来检查python3解释器(如果存在)中的实际绑定的doc字符串<function_name>.__doc__.在这种情况下,你可以看到,outImg是不是显示为可选.这是我安装的输出:

>>> cv2.drawMatchesKnn.__doc__
'drawMatchesKnn(img1, keypoints1, img2, keypoints2, matches1to2, outImg[, matchC
olor[, singlePointColor[, matchesMask[, flags]]]]) -> outImg'

解决方案(注意 - 在Windows安装上验证,而不是Linux)

您可能会注意到该教程的最后一个示例,该示例使用以下代码 - None代替传入outImg.我认为这也适合你的情况.

draw_params = dict(matchColor = (0,255,0),
                   singlePointColor = (255,0,0),
                   matchesMask = matchesMask,
                   flags = 0)

img3 = cv2.drawMatchesKnn(img1,kp1,img2,kp2,matches,None,**draw_params)

你不需要传递所有的draw_paramsdict,你可以尝试传递flagsie

img3 = cv2.drawMatchesKnn(img1,kp1,img2,kp2,matches,None,flags=2)

我已经在全新安装的OpenCV 3上验证了这一点(虽然在Windows上,使用预先构建的二进制文件)

Answer 2

好吧,伙计们,我是一个新手,经过数小时的在线研究后学到很多它似乎是一个错误的错误知道错误(-255)NumpyAllocator,许多网站会建议你打开cv2.cpp文件并注释掉该行163代码,我的建议是如果您使用OpenCV 3.1下载等级到OpenCV 3.0.0

该错误似乎在OpenCV 3.1中,除此之外,在OpenCV.org上记录的使用ORB算法的代码有点过时,它声明 #Initiate enter code hereORB detector enter code hereorb = cv2.ORB()#note你会得到一个错误因为这现在enter code here变为: enter code hereorb = cv2.ORB_create()

这是我在Windows 10上使用OpenCV 3.0.0的代码示例:

  # Example of Brute Force matching base on ORB Algorithm
  #Modify Author : Waheed Rafiq R&D student Birmingham City University UK
  #Original author : OpenCV.org
  #Date Updated : 21/04/2016 : 13:45 

  import numpy as np
  import cv2
  from matplotlib import pyplot as plt 

  img1 = cv2.imread('wr-pb.jpg',0)          # queryImage
  img2 = cv2.imread('Waheed.jpg',0) # trainImage

  # Initiate ORB detector
  orb = cv2.ORB_create()

  # find the keypoints and descriptors with ORB
  kp1, des1 = orb.detectAndCompute(img1,None)
  kp2, des2 = orb.detectAndCompute(img2,None)

  # create BFMatcher object
  bf = cv2.BFMatcher(cv2.NORM_HAMMING, crossCheck=True)

 # Match descriptors.
 matches = bf.match(des1,des2)

 # Sort them in the order of their distance.
 matches = sorted(matches, key = lambda x:x.distance)

 # Draw first 10 matches.
 img3 = cv2.drawMatches(img1,kp1,img2,kp2,matches ,None, flags=2)

 plt.imshow(img3),plt.show()

我希望这会有所帮助,我喜欢堆栈Over flow是互联网上最好的资源.