TypeError：无法在opencv

2024-05-05 • 问答

您好，我正在关注下一个文档“ https://pysource.com/2018/09/25/simple-shape-detection-opencv-with-python-3/”，但遇到下一个错误：

Traceback (most recent call last):
  File "e:/Proyectos/Detecciondeobjetos/Untitled-1.py",line 9,in <module>
    for cnt in contours:
TypeError: 'NoneType' object is not iterable

这是我的代码：

import cv2
import numpy as np
font = cv2.FONT_HERSHEY_COMPLEX

img = cv2.imread("123.png",cv2.IMREAD_GRAYSCALE)
_,threshold = cv2.threshold(img,240,255,cv2.THRESH_BINARY)
_,contours = cv2.findContours(threshold,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)

for cnt in contours:
    approx = cv2.approxPolyDP(cnt,0.01*cv2.arcLength(cnt,True),True)
    cv2.drawContours(img,[approx],(0),5)
    x = approx.ravel()[0]
    y = approx.ravel()[1]
    if len(approx) == 3:
        cv2.putText(img,"Triangle",(x,y),font,1,(0))
    elif len(approx) == 4:
        cv2.putText(img,"Rectangle",(0))
    elif len(approx) == 5:
        cv2.putText(img,"Pentagon",(0))
    elif 6 < len(approx) < 15:
        cv2.putText(img,"Ellipse",(0))
    else:
        cv2.putText(img,"Circle",(0))

cv2.imshow("shapes",img)

cv2.imshow("Threshold",threshold)

cv2.waitKey(0)

cv2.destroyAllWindows()

this is the image i am using

TypeError：无法在opencv

template<int size> constexpr auto createObj(){ // implicitly constexpr ---v constexpr auto enumArray = []{ Enums enum_array[size] = {}; for(int i = 0; i < size ; i++){ //fill array with e1 and e2 } return enum_array; }(); return []<std::size_t... S>(std::index_sequence<S...>) -> decltype(auto) { return Example<double,enumArray[S]...>(); }(std::make_index_sequence<size>()); }

这样，您的for循环...

template<int size>
constexpr auto createObj(){
    //   implicitly constexpr ---v
    constexpr auto enumArray = []{
        Enums enum_array[size] = {};

        for(int i = 0; i < size ; i++){
            //fill array with e1 and e2
        }

        return enum_array;
    }();

    constexpr auto&& [...allEnums] = enumArray;

    return Example<double,allEnums...>();
}

...与...相同

contours == None

for cnt in contours: pass不是容器。 for cnt in None: pass没有2或3或100个可以循环的元素。以下是None

的签名

None

您将其称为：

cv.findContours

我认为您可能已经交换了contours,hierarchy = cv.findContours(image,mode,method[,contours[,hierarchy[,offset]]] )和_,contours = cv2.findContours(threshold,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)的顺序

无论如何，看起来_,contours的返回值为contours,_

TypeError：无法在opencv

okyi1 回答：TypeError：无法在opencv

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